While Argentina has never produced nuclear weapons, Argentina once pursued a covert nuclear weapons program for many years, during which, Argentina refused to accede to the Nuclear Non-Proliferation Treaty (NPT) and did not sign the Treaty for the Prohibition of Nuclear Weapons in Latin America (the Tlatelolco Treaty). A gaseous diffusion enrichment plant was built. Construction of reprocessing facilities was pursued for some time, but was suspended in 1990. A number of sites and facilities were developed for uranium mining, milling, and conversion, and for fuel fabrication. A missile development program was pursued for some years, most notably the Condor II missile program which was active from 1983 until the late 1980s to early 1990s. Argentina's nuclear program was supported by a number of countries: power reactors were supplied by Canada and West Germany, a heavy water plant was supplied by Switzerland, and the Soviet Union was another supplier of nuclear equipment. Hot cells operated from 1969-1972, with no international safeguards; figures on the amount of spent fuel treated in the hot cells vary greatly.
In 1992, Argentina constructed with Brazil a bilateral arrangement to place both countries' nuclear material and facilities under their mutual supervision the Argentinean-Brazilian Agency for Accounting and Control (ABACC), and along with Brazil, signed a comprehensive safeguards agreement with the International Atomic Energy Agency (IAEA). On March 24, 1993 the Argentine Senate ratified the Treaty of Tlatelolco, moving Argentina one step closer to becoming the 25th country to join the 1967 agreement calling for a nuclear-free zone in Latin America and the Caribbean. Later in 1993, Argentina became a member of the Missile Technology Control Regime (MTCR). In 1994, Argentina was invited to join the Nuclear Suppliers Group (NSG) as well.
In February 1995, Argentina acceded to the NPT as a non-nuclear weapon state. The European Union said that Argentina's accession to the NPT confirms its commitment to nuclear non-proliferation, already demonstrated by the quadripartite agreement on nuclear safeguards concluded among Argentina, Brazil, and IAEA, and by the Treaty of Tlateloco. Recently, there have been proposals for Argentina to develop nuclear powered submarines for the Argentine Navy, a move which has been controversial in Argentine politics.