No evidence to support US claim China conducted nuclear blast test: Monitor

Washington wants Beijing to join a new nuclear weapons treaty after expiration of the New START accord between the US and Russia.Published On 7 Feb 2026An international monitor said it has seen no evidence to support the claim by a senior United States official who accused China of carrying out a series of clandestine nuclear tests in 2020 and concealing activities that violated nuclear test ban treaties.US Under Secretary of State for Arms Control and International Security Thomas DiNanno made the assertions about China at a United Nations disarmament conference in Geneva, Switzerland, on Friday, just days after a nuclear treaty with Russia expired.Recommended Stories list of 3 itemslist 1 of 3Trump rejects call from Russia’s Putin to extend cap on nuclear deploymentslist 2 of 3Russia says will act responsibly despite New START nuclear treaty expirylist 3 of 3Just how ‘excellent’ was Trump and Xi Jinping’s phone call, really?end of list“I can reveal that the US government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tonnes,” DiNanno said at the conference.China’s military “sought to conceal testing by obfuscating the nuclear explosions because it recognised these tests violate test ban commitments,” he said.“China conducted one such yield-producing nuclear test on June 22 of 2020,” he said.DiNanno also made his allegations on social media in a series of posts, making the case for “new architecture” in nuclear weapons control agreements following the expiration of the New START treaty with Russia this week.“New START was signed in 2010 and its limits on warheads and launchers are no longer relevant in 2026 when one nuclear power is expanding its arsenal at a scale and pace not seen in over half a century and another continues to maintain and develop a vast range of nuclear systems unconstrained by New START’s terms,” he said.Robert Floyd, executive secretary of the Comprehensive Nuclear-Test-Ban Treaty Organization, said in a statement on Friday that the body’s monitoring system “did not detect any event consistent with the characteristics of a nuclear weapon test explosion” at the time of the alleged Chinese test, adding that that assessment remains unchanged after further detailed analyses.