United States Code, 2018 Edition
Title 22 - FOREIGN RELATIONS AND INTERCOURSE
CHAPTER 7 - INTERNATIONAL BUREAUS, CONGRESSES, ETC.
Sec. 262 - President's participation in international congresses restricted
From the U.S. Government Publishing Office, www.gpo.gov
§262. President's participation in international congresses restricted
The Executive shall not extend or accept any invitation to participate in any international congress, conference, or like event, without first having specific authority of law to do so.
(Mar. 4, 1913, ch. 149, 37 Stat. 913.)