Treaty of Tlatelolco

The Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (commonly known as the Treaty of Tlatelolco) is an international treaty that establishes the nuclear disarmament of Latin America and the Caribbean. It was proposed by Adolfo López Mateos, the President of Mexico, and promoted by the Mexican diplomats Alfonso García Robles, Ismael Moreno Pino and Jorge Castañeda as a response to the Cuban Missile Crisis (1962). For his efforts in favour of the reduction of nuclear weapons, García Robles was awarded the Nobel Peace Prize in 1982.

The following year, López Mateos invited President of Bolivia Víctor Paz Estenssoro, President of Brazil João Goulart, President of Chile Jorge Alessandri, and President of Ecuador Carlos Julio Arosemena Monroy to make a public statement following the Crisis. They issued a Joint Declaration on 29 April 1963, announcing their intent to undertake a multilateral Latin American nuclear agreement. The presentation of the Joint Declaration at the United Nations General Assembly (UNGA) authorised Mexico to lead the treaty's drafting. The 18th session of the UNGA approved the Preliminary Meeting on the Denuclearization of Latin America (REUPRAL), held from 23 to 27 November 1964. During the first session, REUPRAL established the Preparatory Commission for the Denuclearization of Latin America (COPREDAL).

The preparation of the text was entrusted to the COPREDAL, which established its headquarters in Mexico City and held four plenary sessions. The draft was approved on 12 February 1967. The treaty was opened for signature on 14 February 1967 and entered into force on 25 April 1969. It was the first treaty of its kind covering a populated area of the world, establishing a nuclear-weapon-free zone stretching from the Rio Grande to Tierra del Fuego.

The organisation in charge of monitoring compliance with the treaty is OPANAL (Agency for the Prohibition of Nuclear Weapons in Latin America and the Caribbean).