Action 11 - NPT Monitor

China

What has the NWS done so far (prior to the current Review Cycle 2022–2026)?

China has maintained its nuclear-testing moratorium since 1996.

China has supported CTBT objectives and participated in the development of the CTBT verification regime.

At the same time, external analysts, including those from the U.S. government, have raised concerns about construction activity at Lop Nur, although China has denied any intention to conduct nuclear tests.

China has expanded its contribution to the International Monitoring System:

As of 2014, China has undertaken the construction work of 11 monitoring stations and one radionuclide laboratory of the International Monitoring System, of which 6 seismic stations, 3 radionuclide stations, the Beijing radionuclide laboratory and the National Data Center in Beijing have been completed.
As of 2019, radionuclide stations in Beijing, Guangzhou, Lanzhou, and seismic stations in Hailar, Lanzhou have been certified and began real-time data transmission; China has accelerated the certification of remaining infrasound stations (e.g., Kunming).

What is the NWS doing on this action in the current Review Cycle 2022–2026?

China has continued to observe its testing moratorium and has stated that it will not become an obstacle to CTBT entry into force.

China has continued to participate in CTBTO work and has completed and certified China’s IMS stations, feeding data to the international system.

Concerns remain among external analysts regarding infrastructure expansion at the Lop Nur test site, due to limited official explanation.

Sources

Implementation of the Treaty on the Non-Proliferation of Nuclear Weapons–Report submitted by the People’s Republic of China, NPT/CONF.2015/32, 17 April 2015

Implementation of the Treaty on the Non-Proliferation of Nuclear Weapons in the People’s Republic of China, NPT/CONF.2020/41, 28 January 2022

White Paper: China’s Arms Control, Disarmament, and Nonproliferation in the New Era, State Council Information Office, November 27, 2025

Remarks by Ambassador Geng Shuang at the Thirteenth Conference on Facilitating the Entry into Force of the CTBT, September 22, 2023

Chinese nuclear weapons, 2024, January 15, 2024

France

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What has the NWS done so far (prior to the current Review Cycle 2022–2026)?

France definitively ended its nuclear testing in 1996 and dismantled in an irreversible manner its nuclear testing facilities in French Polynesia.

France built simulation capacities which are it presents as a sustainable substitute to nuclear testing to ensure the safety and reliability of its nuclear arsenal, without resorting to nuclear testing.

What is the NWS doing on this action in the current Review Cycle 2022–2026?

France has continued to refrain from nuclear-weapon testing and to use and develop its simulation programme.

Sources

National Report submitted by France. Report submitted by France under actions 5, 20 and 21 of the Final Document of the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (2022–2026). NPT/CONF.2026/PC.III/2. 7 March 2025, https://docs.un.org/en/NPT/CONF.2026/PC.III/2

Russia

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What has the NWS done so far (prior to the current Review Cycle 2022–2026)?

Russia has maintained a national moratorium on nuclear testing since its last explosive nuclear test in 1990.

What is the NWS doing on this action in the current Review Cycle 2022–2026?

In November 2023 Russia has revoked its ratification of the CTBT. Russia continued to be a signatory to the CTBT and to participate in the work of the CTBTO.

Russia has reaffirmed its full commitment to the goals and objectives of the CTBT, as well as to efforts to ensure its entry into force in official statements.

In 2026 Russia reaffirmed that it intends to continue observing the national moratorium on nuclear testing, provided that other nuclear-weapon States adhere to a similar approach.

Sources

United Nations. Russian Federation: Withdrawal of the instrument of ratification, 2 November 2023

https://treaties.un.org/doc/Publication/CN/2023/CN.463.2023-Eng.pdf

Mikhail Ulyanov. Statement by Permanent Representative of the Russian Federation to the International Organizations in Vienna at the 65th session of the CTBTO Preparatory Commission, 10 November 2025.

https://viennamission.mid.ru/en/news/statement_by_permanent_representative_of_the_russian_federation_to_the_international_organizations_i_101125/

National report of the Russian Federation, 2026 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (New York), 2 March 2026.

https://docs.un.org/en/NPT/CONF.2026/14

United Kingdom

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What has the NWS done so far (prior to the current Review Cycle 2022–2026)?

The United Kingdom has not conducted a yield-generating nuclear weapons test since 26 November 1991. It ratified the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1998 and is a member of the CTBT Preparatory Commission (CTBTO).

What is the NWS doing on this action in the current Review Cycle 2022–2026?

On Russia’s nuclear testing posture, the UK and France issued a joint statement in April 2023 expressing concern over Russia’s announcement that it would ensure its preparedness to conduct a nuclear test, and reiterating the importance of the CTBT and of Russia’s compliance with its moratorium on nuclear tests.

In November 2025 the government was asked in the House of Lords “ what assessment they have made of President Trump’s statement on 30 October regarding the testing of nuclear weapons”. The government replied that “We remain committed to our voluntary moratorium on nuclear test explosions, having ceased nuclear testing in 1991. The nuclear testing policy of the United States is a matter for the US Government, and it would therefore be inappropriate to comment further.”

Sources

Foreign, Commonwealth and Development Office (2023). Comprehensive Nuclear Test Ban Treaty 25th anniversary: UK and France statement. 6 April. https://www.gov.uk/government/news/uk-france-statement-on-25th-anniversary-of-the-comprehensive-nuclear-test-ban-treaty

House of Lords (2025). President Trump: Nuclear Weapons Statement. Volume 850. 20 November. https://hansard.parliament.uk/lords/2025-11-20/debates/CED7F0A3-4551-4E74-A14C-BA3538E79255/PresidentTrumpNuclearWeaponsStatement

United States

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What has the NWS done so far (prior to the current Review Cycle 2022–2026)?

Between 1945 and 1992, the United States conducted 1054 nuclear test explosions, with its final test occurring on September 23, 1992. That year, the Hatfield-Exon-Mitchell amendment to the fiscal year 1993 energy appropriations bill was passed into law, which established a limited moratorium on nuclear testing and stated that “no underground test of nuclear weapons may be conducted by the United States after September 30, 1996, unless a foreign state conducts a nuclear test after this date, at which time the prohibition on United States nuclear testing is lifted.” The United States has continued to abide by the moratorium following the conclusion of the 1996 Comprehensive Test Ban Treaty (CTBT), although it ultimately did not ratify the treaty and thus has not facilitated its entry into force.

To sustain the United States’ nuclear arsenal without returning to testing, the Clinton administration established the Stockpile Stewardship Program to obtain technical information about the stockpile through subcritical experiments, computer simulations, and diagnostic tests.

Although it continued to abide by the testing moratorium, the Trump administration’s 2018 Nuclear Posture Review explicitly stated that it “will not seek ratification of the Comprehensive Nuclear Test Ban Treaty.”

What is the NWS doing on this action in the current Review Cycle 2022–2026?

Throughout the review period, the United States continued to observe its moratorium on zero-yield nuclear explosive testing and did not conduct a nuclear explosive test.

Biden administration officials, including the NNSA Administrator, reiterated on multiple occasions that there was no technical need for the United States to resume nuclear testing. In a demonstration of transparency, in 2022 and 2023 journalists and civil society experts were invited to tour the Nevada National Security Site to view the United States’ stockpile stewardship capabilities, and representatives from NPT States parties were invited to Sandia National Laboratories and Los Alamos National Laboratory for transparency visits. These transparency visits were largely intended to indicate that the United States can continue to sustain its nuclear arsenal without resorting to nuclear testing.

The second Trump administration appears to be attempting to reverse these longstanding U.S. policy positions. In October and November 2025, President Trump made numerous statements indicating that he would begin the process of resuming U.S. nuclear testing. State Department officials subsequently clarified that the President was referring to explosive low-yield nuclear testing, similar to the experiments that the United States had accused Russia and China of conducting. As of April 2026, the United States had not conducted a nuclear explosive test.

Sources

National Nuclear Security Administration Nevada Field Office. “United States Nuclear Tests: July 1945 through September 1992.” U.S. Department of Energy, DOE/NV—209-REV 16, September 2015. https://nnss.gov/wp-content/uploads/2023/08/DOE_NV-209_Rev16.pdf.

“Energy and Water Development Appropriations Act, 1993.” Public Law No. 102-377. https://www.congress.gov/102/statute/STATUTE-106/STATUTE-106-Pg1315.pdf.

Nevada National Security Sites. “Stockpile Stewardship.” National Nuclear Security Administration. https://nnss.gov/mission/stockpile-stewardship-program/.

U.S. Department of Defense. Nuclear Posture Review 2018. Washington, DC: Office of the Secretary of Defense, February 2018. https://fas.org/wp-content/uploads/media/2018-Nuclear-Posture-Review-Version-2.pdf.

Kimball, Daryl G., and Carol Giacomo. “Managing an Arsenal Without Nuclear Testing: An Interview With Jill Hruby of the U.S. National Nuclear Security Administration.” Arms Control Today, December 2023. https://www.armscontrol.org/act/2023-12/interviews/managing-arsenal-without-nuclear-testing-interview-jill-hruby-us-national.

National Nuclear Security Administration. “Two NNSA National Labs host Nuclear Non-Proliferation Treaty representatives from around the world for transparency visit.” July 21, 2022. https://www.energy.gov/nnsa/articles/two-nnsa-national-labs-host-nuclear-non-proliferation-treaty-representatives-around.

National Nuclear Security Administration. “NNSA demonstrates transparency during arms control and nonproliferation experts’ visit to Nevada.” December 1, 2023. https://www.energy.gov/nnsa/articles/nnsa-demonstrates-transparency-during-arms-control-and-nonproliferation-experts-visit.

Brumfiel, Geoff. “Step Inside the Secret Lab Where America Tests Its Nukes.” January 29, 2025, NPR, https://www.npr.org/2025/01/29/nx-s1-5276315/atomic-bomb-nuclear-weapons-lab-nevada.

Trump, Donald (@realDonaldTrump). “The United States has more Nuclear Weapons than any other country. This was accomplished, including a complete update and renovation of existing weapons, during my First Term in office. Because of the tremendous destructive power, I HATED to do it, but had no choice! Russia is second, and China is a distant third, but will be even within 5 years. Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis. That process will begin immediately. Thank you for your attention to this matter! PRESIDENT DONALD J. TRUMP.” Truth Social, October 29, 2025. https://truthsocial.com/@realDonaldTrump/posts/115460423936412555.

O’Donnell, Norah. “President Trump on nuclear testing, the government shutdown, immigration, tariffs and U.S.-China relations.” CBS News, November 2, 2025. https://www.cbsnews.com/news/trump-on-nuclear-testing-government-shutdown-immigration-tariffs-china-60-minutes-transcript/.

Gordon, Michael, and Robbie Gramer. “U.S. Accuses China of Secretly Conducting Nuclear Tests.” Wall Street Journal, February 6, 2025. https://www.wsj.com/world/china/u-s-accuses-china-of-secretly-conducting-nuclear-tests-fd728b6e.