[Senate Treaty Document 118-1]
[From the U.S. Government Publishing Office]






118th Congress    }                                 {      Treaty Doc. 
                                 SENATE
 1st Session      }                                 {           118-1 
_______________________________________________________________________

                                     

 
THE TREATIES WITH THE REPUBLIC OF CUBA AND THE GOVERNMENT OF THE UNITED 
       MEXICAN STATES ON THE DELIMITATION OF MARITIME BOUNDARIES

                               __________

                                MESSAGE

                                  from

                     THE PRESIDENT OF THE UNITED STATES

                              transmitting

  THE TREATY BETWEEN THE UNITED STATES OF AMERICA AND THE REPUBLIC OF 
 CUBA ON THE DELIMITATION OF THE CONTINENTAL SHELF IN THE EASTERN GULF 
    OF MEXICO BEYOND 200 NAUTICAL MILES, AND THE TREATY BETWEEN THE 
 GOVERNMENT OF THE UNITED STATES OF AMERICA AND THE GOVERNMENT OF THE 
 UNITED MEXICAN STATES ON THE DELIMITATION OF THE MARITIME BOUNDARY IN 
THE EASTERN GULF OF MEXICO, BOTH OF WHICH WERE SIGNED AT WASHINGTON ON 
                            JANUARY 18, 2017






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 December 18, 2023.--Treaty was read the first time, and together with 
the accompanying papers, referred to the Committee on Foreign Relations 
           and order to be printed for the use of the Senate  
           
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                 U.S. GOVERNMENT PUBLISHING OFFICE
                 
49-118                   WASHINGTON : 2023 

           
           
           
           
           
           
           
           
           
           
           
           
           
           
                         LETTER OF TRANSMITTAL

                              ----------                              

                                The White House, December 18, 2023.
To the Senate of the United States:
    With a view to receiving the advice and consent of the 
Senate to ratification, I transmit herewith two bilateral 
maritime boundary Treaties: the Treaty between the United 
States of America and the Republic of Cuba on the Delimitation 
of the Continental Shelf in the Eastern Gulf of Mexico beyond 
200 Nautical Miles (the ``United States-Cuba Treaty''), and the 
Treaty between the Government of the United States of America 
and the Government of the United Mexican States on the 
Delimitation of the Maritime Boundary in the Eastern Gulf of 
Mexico (the ``United States-Mexico Treaty'') (together, the 
``Treaties''), both of which were signed at Washington on 
January 18, 2017. I also transmit, for the information of the 
Senate, the report of the Department of State with respect to 
the Treaties.
    The purpose of the Treaties is to establish our continental 
shelf boundaries in the eastern Gulf of Mexico with Cuba and 
Mexico in areas beyond 200 nautical miles from shore. The 
United States-Cuba Treaty establishes a maritime boundary of 
approximately 30 nautical miles in length, and the United 
States-Mexico Treaty establishes a maritime boundary of 
approximately 79 nautical miles in length. The boundaries 
define the limit within which each country may exercise 
maritime jurisdiction with respect to its portion of the 
continental shelf. The boundaries address the only remaining 
area in the Gulf of Mexico where the maritime boundaries 
between the United States and its neighbors had not been 
agreed.
    The United States-Cuba Treaty also establishes procedures 
for addressing the possibility of oil and gas reservoirs that 
extend across the continental shelf boundary, which will help 
protect related United States interests. With respect to 
Mexico, such procedures were developed and set forth in a 
separate agreement that is already in force, as described in 
the report of the Department of State accompanying this 
message.
    I believe the Treaties to be fully in the interest of the 
United States. In light of the relevant coastal geography, the 
Treaties allocate approximately two-thirds of the area in 
question to the United States, and they provide legal certainty 
with respect to United States sovereign rights and jurisdiction 
over the continental shelf.
    I recommend that the Senate give early and favorable 
consideration to the Treaties, and give its advice and consent 
to ratification.
                                               Joseph R. Biden, Jr.  
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                                               
                          LETTER OF SUBMITTAL

                              ----------                              

                                       Department of State,
                                      Washington, October 17, 2023.
The President,
The White House.
    I have the honor to submit to you, with a view to the 
transmittal to the Senate for its advice and consent to 
ratification, two bilateral treaties delimiting the maritime 
boundaries between the United States and our neighbors in the 
eastern Gulf of Mexico. The Treaty between the United States of 
America and the Republic of Cuba on the Delimitation of the 
Continental Shelf in the Eastern Gulf of Mexico beyond 200 
Nautical Miles (the ``U.S.-Cuba Treaty''), and the Treaty 
between the Government of the United States of America and the 
Government of the United Mexican States on the Delimitation of 
the Maritime Boundary in the Eastern Gulf of Mexico (the 
``U.S.-Mexico Treaty''), were each signed at Washington on 
January 18, 2017. For purposes of illustration only, the 
boundaries are depicted on maps attached to the Treaties.
    The Treaties define the limits within which each Party may 
exercise its sovereign rights over the seabed and subsoil of 
the continental shelf in the area in the eastern Gulf of Mexico 
beyond 200 nautical miles from any country (i.e., beyond the 
limits of the Parties' respective exclusive economic zones, or 
EEZs). Previous U.S. bilateral treaties with each country 
establish the maritime boundaries in areas within 200 nautical 
miles: specifically, (1) the Treaty to Resolve Pending Boundary 
Differences and Maintain the Rio Grande and Colorado River as 
the International Boundary, signed at Mexico City, November 23, 
1970, which entered into force April 18, 1972 (``1970 U.S.-
Mexico Treaty''); (2) the Treaty on Maritime Boundaries between 
the United States of America and the United Mexican States, 
signed at Mexico City, May 4, 1978, which entered into force 
November 13, 1997 (``1978 U.S.-Mexico Treaty''); and (3) the 
Maritime Boundary Agreement between the United States of 
America and the Republic of Cuba, signed at Washington, 
December 16, 1977 (``1977 U.S.-Cuba Treaty''), which has not 
entered into force and is pending Senate advice and consent. In 
addition, the Treaty between the Government of the United 
States of America and the Government of the United Mexican 
States on the Delimitation of the Continental Shelf in the 
Western Gulf of Mexico beyond 200 Nautical Miles, signed at 
Washington on June 9, 2000 (``2000 U.S.-Mexico Treaty''), which 
entered into force on January 17, 2001, delimits an area of 
continental shelf beyond 200 nautical miles in the western Gulf 
of Mexico.
    The two Treaties submitted herein, pertaining to an area of 
continental shelf in the eastern Gulf of Mexico beyond 200 
nautical miles from any country, delimit the final remaining 
part of the U.S. maritime boundaries in the Gulf of Mexico. 
They achieve the U.S. objective of delimiting boundaries 
consistent with the approach taken in previous boundary 
treaties with Cuba and Mexico and will enhance international 
recognition with respect to U.S. sovereign rights and 
jurisdiction over the continental shelf.
Breadth of the continental shelf
    The 1958 Convention on the Continental Shelf (the ``1958 
Convention''), to which the United States and Mexico (but not 
Cuba) are parties, provides that the continental shelf of a 
coastal State extends beyond a depth of 200 meters to ``where 
the depth of superjacent waters admits of the exploitation of 
the natural resources'' of the shelf. The 1982 United Nations 
Convention on the Law of the Sea (the ``1982 Convention''), to 
which Mexico and Cuba are parties and which the United States 
regards as customary international law in this respect, 
provides the modern, internationally accepted definition of the 
continental shelf. Article 76 of the 1982 Convention provides 
that the continental shelf of a coastal nation extends (1) 200 
nautical miles from the coastal baselines (typically the low-
water line along the coast) or (2) to the outer edge of the 
continental margin, whichever is farther seaward. Under either 
criterion of the 1982 Convention (i.e., 200 nautical miles or 
the continental margin) as well as under the 1958 Convention, 
the coastal nation has exclusive control over the exploration 
and exploitation of the natural resources, including critical 
minerals and hydrocarbons, of the continental shelf.
    With respect to seabed areas beyond 200 nautical miles from 
the coastal baselines, paragraphs 2 to 7 of Article 76 provide 
the detailed rules that must be met to qualify as continental 
shelf of a coastal nation. The United States considers that 
these provisions reflect customary international law. During 
the negotiations of the 2017 treaties, all three countries 
agreed that, based on the detailed rules in Article 76, each 
country is entitled to continental shelf in the entire area 
beyond the 200-mile EEZ limit allocated to that country under 
the Treaties.
Maritime Boundaries
    The U.S.-Cuba Treaty consists of nine articles and two 
annexes. The U.S.-Mexico Treaty consists of nine articles and 
one annex. The form and content of the two treaties are similar 
to each other and are also similar to previous maritime 
boundary treaties between the United States and Mexico and 
between the United States and Cuba.
    Article I of each Treaty describes the continental shelf 
boundary between the United States and the other Party in the 
eastern Gulf of Mexico beyond 200 nautical miles as geodetic 
lines connecting the listed points. The U.S.-Mexico Treaty 
lists coordinates for seven turning and terminal points, and 
the U.S.-Cuba Treaty lists coordinates for two terminal points 
connected by a single geodetic line. In keeping with the 
methodology used in previous U.S. maritime boundary treaties in 
the Gulf of Mexico, these lines represent equidistant lines 
drawn from the respective coastline of each Party, including 
from islands.
    Article II of each Treaty sets out the technical parameters 
of the boundary. Specifically, Article II states that the 
geodetic and computational bases used to determine the boundary 
are, in the case of the U.S.-Cuba Treaty, the World Geodetic 
System 1984 (``WGS84''), and in the case of the U.S.-Mexico 
Treaty, both WGS84 and the International Terrestrial Reference 
Frame 2008 (``ITRF2008''), which it specifies shall be 
considered identical. This article is needed to ensure that the 
Treaty boundaries are applied uniformly and accurately by the 
United States, Cuba, and Mexico, as well as all other users. 
Article II of each Treaty further clarifies that the western 
end of the new U.S.-Mexico boundary and the eastern end of the 
new U.S.-Cuba boundary connect to the terminal points of the 
boundaries that have previously been agreed with each country 
for areas within 200 nautical miles of shore. For the other 
terminal point of each boundary line, the coordinates specified 
in Article I in each Treaty are identical, such that the U.S.-
Mexico and U.S.-Cuba boundary lines are coterminous; clarifying 
the method by which this shared point was chosen, Article II of 
each Treaty states that this point represents a single ``tri-
point,'' equidistant from all three countries. (Cuba and Mexico 
simultaneously negotiated their own equidistance-based maritime 
boundary treaty in this area, and it too terminates at this 
tri-point.) Further, Article II states that, for the purpose of 
illustration only, a map depicting the boundary is attached to 
the Treaty as an annex (Annex 1 in the case of the U.S.-Cuba 
Treaty, and the only Annex in the case of the U.S.-Mexico 
Treaty).
    Article III of each Treaty sets forth the agreement of the 
Parties that, on the opposite side of each maritime boundary, 
each Party will not ``claim or exercise for any purpose 
sovereignty, sovereign rights, or jurisdiction over the seabed 
and subsoil.'' This is consistent with standard language in all 
modern U.S. maritime boundary agreements. Because the boundary 
in each of these two Treaties delimits the continental shelf 
beyond 200 nautical miles from the coast, this Article mentions 
only the seabed and subsoil, and not the ``waters,'' which are 
not part of the continental shelf.
    While negotiating the U.S.-Mexico Treaty, however, it was 
discovered that owing to coastal changes and updated 
measurements, some of the terminal points of the boundary 
segments delimited in the 1978 U.S.-Mexico Treaty may in fact 
currently fall slightly less than 200 nautical miles from 
shore. Accordingly, Article IV of the new U.S.-Mexico Treaty 
clarifies that, to the extent that any portion of the new 
boundary line ever falls within 200 nautical miles of the 
coastal baselines (i.e., where the United States or Mexico 
claims an exclusive economic zone), that portion of the 
boundary also applies with respect to sovereign rights or 
jurisdiction over the ``waters,'' in addition to the seabed and 
subsoil. Article IV is the only provision of the new Treaty 
that also by its terms applies with respect to the boundary 
line set forth in the 2000 U.S.-Mexico Treaty regarding the 
continental shelf boundary beyond 200 nautical miles in the 
western Gulf of Mexico. While problems in the absence of 
Article IV may not have been likely as a practical matter (and 
there is no indication that such problems have arisen with 
respect to the 2000 boundary), this technical provision and its 
application to both continental shelf areas of the Gulf of 
Mexico beyond 200 nautical miles will help avoid ambiguity. No 
such provision was needed in the U.S.-Cuba Treaty; the terminal 
point of the adjacent 1977 U.S.-Cuba boundary is not less than 
200 nautical miles offshore.
Transboundary reservoirs
    Article V of the U.S.-Mexico Treaty, and Articles IV and V 
of the U.S. Cuba Treaty, contain provisions pertaining to 
possible hydrocarbon reservoirs that may extend across the 
continental shelf boundary (hereinafter, ``transboundary 
reservoirs'').
    To date, there has not been any drilling for hydrocarbons 
by any country in the eastern Gulf of Mexico beyond 200 
nautical miles. These two Treaties do not in any way compel the 
United States or either other Party to explore or exploit the 
natural resources in the area on its side of the boundary 
beyond 200 nautical miles, nor do they prohibit such activity 
(except in a narrow buffer zone along the U.S.-Cuba boundary 
where drilling is temporarily prohibited, as described below); 
that decision remains in the discretion of each country, 
consistent with applicable international law. Instead, 
provisions in the treaties address the potential need for 
cooperation and periodic consultation between the Parties in 
protecting their respective interests pertaining to 
transboundary reservoirs.
    Article V of the U.S.-Mexico Treaty states that ``[t]he 
maritime boundary set forth in Article I will constitute a 
delimitation line as defined in Article 2 of the 2012 
Transboundary Hydrocarbon Reservoirs Agreement, such that the 
provisions of that Agreement become applicable to the maritime 
boundary upon entry into force of this Treaty.'' This provision 
refers to the Agreement between the United States of America 
and the United Mexican States Concerning Transboundary 
Hydrocarbon Reservoirs in the Gulf of Mexico, which was signed 
at Los Cabos on February 20, 2012, and entered into force on 
July 18, 2014 (the ``2012 U.S.-Mexico Transboundary Hydrocarbon 
Reservoirs Agreement''). The 2012 U.S.-Mexico Transboundary 
Hydrocarbon Reservoirs Agreement establishes a cooperative 
process for managing the maritime boundary region and addresses 
the joint utilization of transboundary reservoirs.
    The provisions of the 2012 U.S.-Mexico Transboundary 
Hydrocarbon Reservoirs Agreement will apply with respect to the 
boundary in this new U.S.-Mexico Treaty upon its entry into 
force. By its terms, the 2012 Transboundary Hydrocarbon 
Reservoirs Agreement applies with respect to the ``Delimitation 
Line,'' which Article 2 of that agreement defines as ``the 
maritime boundaries in the Gulf of Mexico delimited in the 1970 
U.S.-Mexico Treaty, the 1978 U.S.-Mexico Treaty and the 2000 
U.S.-Mexico Treaty, and any furture maritime boundary in the 
Gulf of Mexico delimited between the Parties, as agreed'' 
(emphasis added).
    Between the United States and Cuba, there is no analogous, 
previous agreement on transboundary hydrocarbons. The United 
States has an interest in greater cooperation with Cuba on such 
issues, however, both to protect U.S. interests in any 
transboundary resources and to develop and maintain a better 
understanding of the Cuban regulatory regime for offshore 
hydrocarbon development within areas under Cuban jurisdiction, 
including to encourage Cuba to follow international best 
practices with respect to any such activity, such as with 
respect to safety and protection of the marine environment. 
Consequently, as described below, Articles IV and V of the 
U.S.-Cuba Treaty are almost identical to the provisions to 
which the United States and Mexico agreed in the 2000 U.S.-
Mexico Treaty concerning the continental shelf beyond 200 
nautical miles in the western Gulf of Mexico.
    Article IV(1) creates a buffer zone, called ``the Area,'' 
which comprises a continental shelf area with a breadth of 1.4 
nautical miles on each side of the boundary. Within the Area, 
the Parties agree to a moratorium on petroleum and natural gas 
drilling or exploitation through December 31, 2026. By its 
terms, the moratorium does not apply to other continental shelf 
activities. Each Party's right to authorize or permit such 
drilling or exploitation outside the Area on its side of the 
boundary is unaffected by this moratorium.
    Article IV(2) provides that the Area is shown on an 
illustrative map at Annex 2 of the Treaty.
    Article IV(3) establishes that the Parties may modify the 
period of the moratorium applicable in the Area by mutual 
agreement through an exchange of diplomatic notes. This 
provision will enable the Parties to shorten or to extend the 
duration of the moratorium should they both agree.
    Article IV(4) requires each Party, on its side of the 
boundary within the Area and in accordance with its national 
laws and regulations, to facilitate requests from the other 
Party to authorize geological and geophysical studies for 
determining the possible presence and distribution of 
transboundary reservoirs.
    Article IV(5) requires that each Party, with respect to the 
Area in its entirety and in accordance with its national laws 
and regulations, share geological and geophysical information 
in its possession to determine the possible existence and 
location of transboundary reservoirs.
    Article IV(6) obliges each Party, if it has knowledge of 
the existence or possible existence of any transboundary 
reservoir, to notify the other Party.
    Article V of the Treaty details a mechanism for 
communication and cooperation between the Parties with respect 
to the Area and the possible existence and location of 
transboundary reservoirs.
    Article V(1) provides that that the Parties, with respect 
to the Area during the moratorium period, shall:
    --meet at least once per year for the purpose of 
identifying, locating, and determining the geological and 
geophysical characteristics of transboundary reservoirs as 
geological and geophysical information is generated that 
facilitates the Parties' knowledge about the possible existence 
of such reservoirs (including information provided under 
Article IV(5) and IV(6));
    --seek to reach agreement for the efficient and equitable 
exploitation of such transboundary reservoirs; and
    --consult within sixty days of receipt of a written request 
by a Party through diplomatic channels, to discuss matters 
related to possible transboundary reservoirs.
    Article V(2) further requires, with respect to the Area, 
that following the moratorium period, the Parties shall:
    --inform the other Party both of its decisions to lease, 
license, grant concessions, or otherwise make available 
portions of the Area for petroleum or natural gas exploration 
or development and when petroleum or natural gas resources are 
to commence production; and
    --ensure that entities it authorizes to undertake 
activities in the Area observe the terms of the Treaty.

Dispute resolution and consultations

    Article VI of each Treaty requires the Parties to consult 
to discuss any issue regarding the interpretation or 
implementation of the Treaty upon the written request by a 
Party through diplomatic channels.
    Article VIII of each Treaty provides that any dispute 
concerning the interpretation or application of the Treaty must 
be resolved by negotiation or other peaceful means as may be 
agreed upon by the Parties.

Final clauses

    Article VII of each Treaty provides that the boundary 
established in the Treaty does not affect or prejudice in any 
manner the positions of either Party with respect to the extent 
of internal waters, of the territorial sea, of the high seas, 
or of sovereign rights or jurisdiction for any other purpose 
(including, as the U.S.-Cuba Treaty makes express, with respect 
to the contiguous zone and the exclusive economic zone). This 
is a standard provision in modern U.S. maritime boundary 
treaties and helps ensure, for example, that the boundaries 
cannot be misconstrued as somehow respecting or acquiescing in 
any unlawful maritime claims made by Cuba or Mexico.
    Article IX of each Treaty specifies that an exchange of 
diplomatic notes or instruments of ratification is necessary 
before the Treaty will enter into force. Specifically, Article 
IX of the U.S.-Cuba Treaty provides that it will enter into 
force on the date of the last note verbale in which the Parties 
indicate that their internal legal requirements have been 
satisfied. Article IX of the U.S.-Mexico Treaty provides that 
it will enter into force thirty days after the date on which 
the Parties exchange instruments of ratification.
    The Treaties are self-executing. No new legislation is 
needed for the United States to meet its obligations under the 
Treaties.
    All interested agencies and departments join the Department 
of State in recommending that these two Treaties delimiting the 
continental shelf boundary beyond 200 nautical miles between 
the United States and Cuba and Mexico, respectively, be 
transmitted to the Senate as soon as possible for its advice 
and consent to ratification.
            Respectfully submitted,
                                                 Antony J. Blinken.
    Enclosures: As stated.


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