ˌNuclear ˌNon-prolifeˈration ˌTreaty, the BrE AmE
an international agreement which aims to prevent ↑ nuclear weapons from spreading around the world, but which allows countries to use nuclear ↑ technology peacefully. In 1970 the US, Britain, and the Soviet Union signed the agreement, followed by China and France in 1992. Since then, 184 other countries without nuclear weapons have agreed to use nuclear technology only for peaceful purposes. The International Atomic Energy Agency has the job of checking that countries are obeying the agreement.