Mexico has the capabilities to manufacture nuclear weapons, but abandoned this possibility with the Treaty of Tlatelolco in 1968 and pledged to only use its nuclear technology for peaceful purposes. In 1970, Mexico's national institute for nuclear research successfully refined weapons grade uranium which is used in the manufacture of nuclear weapons but in April 2010, Mexico agreed to turn over its weapons grade uranium to the United States. Mexico signed the UN treaty on the Prohibition of Nuclear Weapons.