On Friday, August 25, 2017, OPANAL and Soka Gakkai International unveiled at the Plaza de las Tres Culturas, in the Tlatelolco neighborhood of Mexico City, a plaque commemorating the 50th anniversary of the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (known as the Treaty of Tlatelolco), which contains the message:
Here in Tlatelolco was signed in 1967 the first international treaty, in a densely populated area, which prohibits nuclear weapons. The 33 countries of Latin America and the Caribbean have demonstrated that the only way to eliminate the problem of nuclear weapons, which are forces that would lead to the destruction of the world, will be the solidarity effort we all undertake to inaugurate, with the driving force of the Hope, a new era in the history of humanity.
The event was attended by Ambassador Luiz Filipe de Macedo Soares, Secretary-General of OPANAL; Mr. Minoru Harada, President of Soka Gakkai International; and Mr. Nereo Ordaz, President of Soka Gakkai - Mexico.
The event also included the opening of the pictographic exhibition presented by Soka Gakkai International: "Everything you treasure: for a world free of nuclear weapons", which includes images of the humanitarian and environmental consequences of the use of nuclear weapons.
The Treaty of Tlatelolco established the first Nuclear-Weapon-Free Zone in a permanently populated region of the world. The Treaty was opened for signature on February 14, 1967 in the Tlatelolco neighborhood of Mexico City (then headquarters of the Ministry of Foreign Affairs of Mexico). Today, all the 33 States of the region have signed and ratified the Treaty of Tlatelolco. The five nuclear-weapon States (China, France, Russia, the United States, and the United Kingdom), by signing and ratifying the Additional Protocols to the Treaty, undertake to respect the Treaty and not to use or threaten to use nuclear weapons against the States of the region.