Treaty on the Prohibition of Nuclear Weapons At the United Nations in May 2015, the NPT Review Conference failed to produce a final outcome document. However, a humanitarian disarmament movement led to several conferences sponsored by the States. This process was further supported by a General Assembly resolution and a working group devoted to this topic. These extensive discussions culminated in 2017 with the Treaty on the Prohibition of Nuclear Weapons, adopted with the approval of 122 nations. The treaty entered into force on January 22, 2021. Hibakusha representatives present the collected signatures to the President of the United Nations Conference to negotiate a legally binding instrument to prohibit nuclear weapons, leading toward their total elimination. June 2017. Photographs courtesy of Nihon Hidankyo. Ms. Setsuko Thurlow (atomic-bombed at the age of 13) and Mr. Toshiki Fujimori (atomic- bombed at the age of 1) delighted at the adoption of the Treaty. Photographs courtesy of Nihon Hidankyo.