The United States on Friday accused China of secretly carrying out nuclear explosive tests, even as Washington and Moscow acknowledged the need to urgently begin fresh arms control talks following the expiry of the last remaining US–Russia nuclear treaty.
The accusation came as US officials renewed pressure on Beijing to be part of any future nuclear arms agreement.
US secretary of state Marco Rubio said an arms control framework that does not include China would leave the United States and its allies “less safe”, pointing to what he described as China’s rapidly expanding nuclear arsenal.
Speaking at the UN-backed Conference on Disarmament in Geneva, top US arms control official Thomas DiNanno said China had conducted covert nuclear tests and attempted to conceal them.
“The US government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons,” he said, according to news agency AP.
DiNanno alleged that China’s military sought to hide the activity because it knew such tests violated commitments to suspend nuclear testing.
China strongly rejected the claims. Ambassador Shen Jian called the allegations “false narratives and unfounded accusations”, insisting Beijing continues to honour its pledge to suspend nuclear testing.
He said US criticism was aimed at shifting responsibility for nuclear disarmament and justifying what he described as American “nuclear hegemony”, reported AP.
New START expires, Russia and US discuss next steps
The sharp exchange came a day after the New Strategic Arms Reduction Treaty (START) formally expired, removing limits on the world’s two largest nuclear arsenals for the first time in more than 50 years. The agreement had capped each side at 1,550 deployed nuclear warheads.
According to the Kremlin, Russian and US negotiators meeting in Abu Dhabi discussed the future of nuclear arms control and agreed on the need to launch talks quickly.
Kremlin spokesman Dmitry Peskov said both sides understood the importance of acting responsibly and beginning negotiations “as soon as possible”, as per AP.
Russian President Vladimir Putin has offered to stick to New START limits for another year if Washington does the same, but US President Donald Trump has not accepted the proposal.
Trump has instead argued for a new and broader agreement that includes China.
Asked about reports of a possible informal extension of the treaty limits, Peskov dismissed the idea, saying any extension would need to be formal. Meanwhile, the US and Russia have agreed to restore high-level military-to-military dialogue, which had been suspended since 2021.
China rejects talks
Washington says China’s growing nuclear stockpile makes its inclusion essential. Rubio wrote that China’s arsenal had increased from the low 200s to more than 600 warheads since 2020 and could cross 1,000 by 2030.
“As we sit here today, China’s entire nuclear arsenal has no limits, no transparency, no declarations and no controls”, DiNanno added.
China, however, has refused to join disarmament talks at this stage. Shen said Beijing’s nuclear capabilities were not comparable to those of the US or Russia and urged the two biggest nuclear powers to shoulder primary responsibility for disarmament.
He also expressed regret over the expiry of New START and called on Washington to accept Moscow’s offer to temporarily maintain its limits.
Russia and the US together control over 80 per cent of the world’s nuclear warheads, while China’s arsenal is expanding faster than any other country’s.
The lapse of New START has raised fears of a renewed nuclear arms race, with no binding framework now in place to restrain the most destructive weapons.
Despite these concerns, big differences remain over the shape of any future agreement, with Washington pushing for a three-way deal, Moscow suggesting other nuclear powers be included, and Beijing refusing to take part for now.