US says China conducted secret nuclear trial in 2020; 'False narratives', claims Beijing

The United States on Friday charged China with carrying out a clandestine nuclear trial in 2020 while advocating for a fresh, more inclusive arms regulation pact that would encompass Beijing and Moscow.

The allegations at an international disarmament summit underscored major frictions between Washington and Beijing during a critical juncture for nuclear weapon management, following the expiration of the accord restricting US and Russian projectile and warhead installations.

"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 tons," US Under Secretary of State for Arms Control and International Security Thomas DiNanno told a Disarmament Conference in Geneva.

The Chinese military "sought to conceal testing by obfuscating the nuclear explosions because it recognized these tests violate test ban commitments. China has used 'decoupling', a method to decrease the effectiveness of seismic monitoring, to hide their activities from the world," he said.

China had conducted one such "yield-producing test" on 22 June 2020, added DiNanno.

Envoys at the meeting noted the American assertions were new and troubling, according to a report by Reuters.

"China notes that the US continues in its statement to hype up the so-called China nuclear threat. China firmly opposes such false narratives," Jian said.

"It (the US) is the culprit for the aggravation of the arms race," he added.

The 2010 New START accord, which concluded on Thursday, left Russia and the United States for the first time in over 50 years without any mandatory restrictions on their positioning of strategic projectiles and warheads.

Arms control deals are highly complex to negotiate, and the environment has changed significantly since New START was signed.

US President Donald Trump seeks to substitute it with a fresh framework involving China, which is swiftly expanding its personal stockpile.

DiNanno told the Geneva conference: "Today, the United States faces threats from multiple nuclear powers. In short, a bilateral treaty with only one nuclear power is simply inappropriate in 2026 and going forward."

Meanwhile, Shen reiterated that China would not participate in new negotiations at this stage with Moscow and Washington.

"In this new era, we hope the US will abandon Cold War thinking... and embrace common and cooperative security," Shen said.

Previously, the US had forecasted that China would possess more than 1,000 nuclear warheads by the year 2030.