Forty years ago, in the midst of the Cold War, Latin American and the Caribbean States came together to forge a landmark agreement banning nuclear weapons in their region.

The Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean, or the Treaty of Tlatelolco, created the world's first nuclear-weapon-free zone in a populated area. Ever since, this agreement has served as a model for nuclear-weapon-free zones in other regions. Today, virtually the entire southern hemisphere is free of such weapons.

This historic pact has stood the test of time. It prompted an innovative regional verification system to enhance confidence in Treaty compliance, and led to a Protocol committing nuclear-weapon states not to use or threaten to use nuclear weapons against States Parties to the Treaty. More broadly, the agreement represented an important commitment by Latin American and Caribbean governments to use nuclear materials and installations for purely peaceful purposes to the benefit of their citizens.

Mexico's Alfonso García Robles received the Noble Peace Prize in 1982 for his pioneering work in negotiating this Treaty. The silver jubilee of that award, and the 40th Anniversary of the Treaty, present a welcome opportunity to reflect upon the continuing challenges posed by nuclear weapons.

I hope this commemoration can help energize efforts to halt, and reverse, the spread of nuclear weapons. In particular, it can draw attention to the important role of regional efforts in addressing this threat. Together, we should work towards the day when all regions of the world are finally free of nuclear weapons.