U.S. Maritime Boundaries: Agreements and Treaties

Maritime boundaries are vital for both maintaining peaceful borders with our neighbors and clearly delimiting our rights and interests with respect to fishing and marine living resources, mineral and hydrocarbon resources, freedom of navigation, maritime domain awareness and security, and other uses of the sea.

Below are the maritime boundary treaties and related international agreements of the United States on record at the U.S. Department of State. Additional treaty documents may be accessed on our archive: https://2009-2017.state.gov/e/oes/ocns/opa/c28187.htm.

Country List

Canada

• Passamaquoddy Bay (1910) 36 Stat. 2477; Treaty Series 551: Treaty [PDF]
• Delimitation of the Maritime Boundary in the Gulf of Maine, ICJ Judgment (1984) ; [PDF] [485 KB]

Cuba

• Maritime Boundary Agreement between the United States of America and the Republic of Cuba (1977): Treaty [PDF] [288 KB]; Senate Treaty Document 96-8 
• 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 (2017; not yet entered into force)

Kiribati

• Treaty between the Government of the United States of America and the Government of the Republic of Kiribati on the Delimitation of Maritime Boundaries (2013, entered into force: July 19, 2019): Senate Treaty Document 114-13 

Federated States of Micronesia

• Treaty between the Government of the United States of America and the Government of the Federated States of Micronesia on the Delimitation of a Maritime Boundary (2014, entered into force: July 18, 2019): Senate Treaty Document 114-13 

Mexico

• Treaty to Resolve Pending Boundary Differences and Maintain the Rio Grande and Colorado River as the International Boundary (1970): Treaty [PDF] [523 KB]
• Treaty on Maritime Boundaries between the United Mexican States and the United States of America (1978):  Treaty [PDF]; Senate Treaty Document 96-6 
• Treaty between the Government of the United Mexican States and the Government of the United States of America on the delimitation of the continental shelf in the western Gulf of Mexico beyond 200 nautical miles (entry into force: 17 January 2001): Treaty [PDF] [571 KB]; Senate Treaty Document 106-39 
• 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 (2017, not yet entered into force)

New Zealand

• Treaty between the United States of America and New Zealand on the Delimitation of the Maritime Boundary Between Tokelau and the United States of America (1980): Treaty [PDF] [438 KB]; Senate Treaty Document 97-5 
• Treaty between the United States of America and the Cook Islands (1980): Treaty [PDF] [966 KB]

Niue

• Treaty between the Government of the United States of America and the Government of Niue on the Delimitation of a Maritime Boundary (1997): Treaty [PDF] [296 KB]; Senate Treaty Document 105-53 

Russian Federation

• The Agreement between the United States of America and the Union of Soviet Socialist Republics on the Maritime Boundary (1990): Treaty [PDF] [260 KB]; Senate Treaty Document 101-22 

United Kingdom

• Treaty on the delimitation in the Caribbean of a maritime boundary relating to the U.S. Virgin Islands and Anguilla (1993): Treaty [PDF] [154 KB]; Senate Treaty Document 103-23 
• Treaty on the delimitation in the Caribbean of a maritime boundary relating to Puerto Rico/U.S. Virgin Islands and the British Virgin Islands (1993): Treaty [PDF]; Senate Treaty Document 103-23 

Venezuela

• Maritime Boundary Treaty between the United States of America and the Republic of Venezuela (1978): Treaty [PDF] [450 KB]; Senate Treaty Document 96-7 

Chronological List (most recent first)

18 JAN 2017: U.S. – Cuba (Eastern Gulf of Mexico)
18 JAN 2017: U.S. – Mexico (Eastern Gulf of Mexico)
01 AUG 2014: U.S. (Guam) – Federated States of Micronesia
06 SEP 2013: U.S. (Howland, Baker and Jarvis Islands, Kingman Reef, Palmyra Atoll) – Republic of Kiribati
09 JUN 2000: U.S. – Mexico (Western Gulf of Mexico) [571 KB]
13 MAY 1997: U.S. (American Samoa) – Niue [296 KB]
05 NOV 1993: U.S. (Puerto Rico and USVI) – UK (British Virgin Islands)
05 NOV 1993: U.S. (USVI) – UK (Anguilla) [154 KB]
29 SEP 1990: U.S. – Russian Federation / USSR [260 KB]
02 DEC 1980: U.S. (American Samoa) – New Zealand (Tokelau) [438 KB]
11 JUN 1980: U.S. (American Samoa) – Cook Islands [966 KB]
29 MAR 1979: U.S. – Canada (Gulf of Maine, ICJ Judgment)
04 MAY 1978: U.S. (Puerto Rico and USVI) – Venezuela [450 KB]
04 MAY 1978: U.S. – Mexico (Gulf of Mexico and Pacific Ocean)
16 DEC 1977: U.S. – Cuba [288 KB]
23 NOV 1970: U.S. – Mexico (Rio Grande and Colorado River) [523 KB]
01 MAY 1910: U.S. – UK / Canada (Passamaquoddy Bay)