On 20 September 2017, the Treaty on the Prohibition of Nuclear Weapons opened for signature at the United Nations headquarters in New York. That day 50 States signed the treaty, with three (3) States also depositing their instruments of ratification with the Office of Legal Affairs.

Signed on 20th September: Algeria, Austria, Bangladesh, Brazil, Cabo Verde, Central African Republic, Chile, Comoros, Congo, Costa Rica, Cote d’Ivoire, Cuba, Democratic Republic of the Congo, Ecuador, El Salvador, Fiji, Gambia, Ghana, Guatamala, Guyana, Holy See, Honduras, Indonesia, Ireland, Kiribati, Libya, Lichtenstein, Madagascar, Malawi, Malaysia, Mexico, Nepal, New Zealand, Nigeria, Palau, Palestine, Panama, Paraguay, Peru, Phillipines, Samoa, San Marino, Sao Tome and Principe, South Africa, Thailand, Togo, Tuvalu, Uruguay, Vanuatu and Venezuela

Ratified on 20th September: Guyana, Holy See and Thailand.