International Day against Nuclear Tests

2025 Conference on Facilitating the Entry into Force of the Comprehensive Nuclear-Test-Ban Treaty United Nations, New York;   The 14th Conference on Facilitating Entry into Force of the Comprehensive Nuclear-Test-Ban Treaty (Article XIV Conference) will take place at the United Nations in New York on Friday, 26 September 2025. Conference Material Draft Rules of Procedure (CTBT-Art.XIV/2025/1) English | Arabic | Chinese | French | Russian | Spanish Draft Provisional Agenda (CTBT-Art.XIV/2025/2) English | Arabic | Chinese | French | Russian | Spanish Information for participants: Note by the Secretariat (CTBT-Art.XIV-2025-INF.1) English Information for non-governmental organizations: Note by the Secretariat (CTBT-Art.XIV-2025-INF.2) English

The success of the Comprehensive Nuclear-Test-ban Treaty rests on science in the service of diplomacy. Its International Monitoring System (IMS) , already operating with more than 300 stations and laboratories in over 90 countries, uses seismic, hydroacoustic, infrasound and radionuclide technologies to detect any nuclear explosion . Data from this network flow to the International Data Centre in Vienna, where they are processed around the clock and made available to all signatory States. This transparency builds confidence. All States rely on the same objective information to assess adherence to the Treaty and to determine whether a nuclear test has taken place. Even countries that have not yet ratified the Treaty host facilities and benefit from the data. That participation reflects the value and credibility that nations place in a system built through global cooperation. Those benefits extend well beyond peace and security: IMS data contribute to tsunami warning systems, support...

Before the Comprehensive Nuclear-Test-ban Treaty (CTBT) was opened for signature, more than 2,000 nuclear test explosions had been conducted worldwide. Since 1996, that number has fallen to fewer than a dozen. This dramatic decline is no accident. It reflects the strength of the norm created by our Treaty and the value that the international community places on preventing any return to testing . The Treaty is already a proven success. It has brought almost all nuclear testing to an end, placing powerful constraints on the development of new nuclear weapons and the advancement of existing designs , while fostering a strong international expectation that testing belongs in the past . Entry into force will build upon this, giving us the full range of verification measures , including on-site inspections , to further reinforce what has already been achieved.