The Treaty on the Prohibition of Nuclear Weapons (TPNW) is the first globally applicable multilateral agreement to comprehensively prohibit nuclear weapons. It is also the first to include provisions to help address the humanitarian consequences of nuclear weapon use and testing. The Treaty complements existing international agreements on nuclear weapons, in particular the Treaty on the Non-Proliferation of Nuclear Weapons, the Comprehensive Nuclear-Test-Ban Treaty and agreements establishing nuclear-weapon-free zones.
The TPNW was adopted by a United Nations diplomatic conference on 7 July 2017 and opened for signature on 20 September 2017. The treaty enters into force on 22 January 2021, after the 50th ratification was deposited on 24 October 2020.