US Reveals Details of Alleged Chinese Nuclear Test, Urges Global Disarmament Talks

Washington Warns China Could Reach Nuclear Parity Within Five Years

A senior United States Arms Control official has disclosed newly declassified information regarding what Washington describes as a suspected underground Chinese nuclear test conducted more than six years ago. The revelation comes amid growing concerns over the rapid expansion of china’s nuclear arsenal and renewed warnings about the potential for a global arms race.

Speaking on Monday at the United Nations-supported Conference on Disarmament in Geneva, Christopher Yeaw, Assistant Secretary of State for the Bureau of Arms Control, Deterrence and Stability, urged countries to apply pressure on both China and Russia to take further steps toward nuclear arms reduction and transparency.

The remarks follow the expiration of the New START treaty — the last remaining nuclear arms control agreement between the United States and Russia. With the treaty now lapsed, formal limitations on the world’s two largest nuclear arsenals have ended, intensifying fears of unchecked weapons expansion.

Concerns Over China’s Expanding Nuclear Arsenal

Yeaw highlighted what he described as significant shortcomings of the New START treaty, particularly its failure to account for China’s rapidly growing nuclear capabilities. While the treaty focused on strategic weapons held by the United States and Russia, it did not impose limits on Moscow’s estimated stockpile of up to 2,000 non-strategic nuclear warheads. Nor did it include any restrictions on Beijing’s arsenal.

Addressing the conference, Yeaw stated that one of New START’s greatest flaws was its inability to address what he called China’s “unprecedented, deliberate, rapid, and opaque” nuclear weapons buildup.

According to US assessments, China has significantly expanded its nuclear stockpile despite publicly maintaining that it adheres to a minimal deterrence policy. Yeaw said Washington believes Beijing could achieve nuclear parity with the United States within the next four to five years if current trends continue.

“We believe China may achieve parity within the next four or five years,” Yeaw warned, emphasizing the need for greater transparency regarding Beijing’s long-term nuclear objectives.

Details of the Alleged 2020 Nuclear Test

During his address, Yeaw provided new details about a seismic event detected on June 22, 2020, at the Lop Nur underground test site in western China. According to data collected from an international monitoring system station in neighboring Kazakhstan, the event registered as a magnitude 2.75 seismic occurrence.

US analysts assessed that the seismic signals were more consistent with a single underground explosive event rather than typical mining activity. Yeaw stated that comparisons with historical nuclear explosions and earthquake data supported the assessment that it was likely a yield-producing test.

He further accused China of making it difficult for the international community to monitor its nuclear testing activities. According to Yeaw, Beijing has resisted efforts to establish seismic monitoring stations near its test sites comparable to those permitted by the United States near its Nevada facility.

China Strongly Denies Accusations

China’s ambassador to the Conference on Disarmament, Jian Shen, firmly rejected the allegations, calling them “unfounded accusations” and accusing Washington of distorting China’s nuclear policy.

Shen stated that China has consistently supported the objectives of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), adhered to commitments by nuclear weapons states to suspend nuclear testing, and never engaged in treaty-violating activities.

He further argued that China’s nuclear arsenal remains significantly smaller than those of the United States and Russia, making it “unfair, unreasonable, and unfeasible” to demand that Beijing participate in three-way arms limitation negotiations.

Broader Debate Over Nuclear Testing

The allegations have reignited debate within the United States about whether Washington should resume nuclear testing. Some American nuclear scientists argue that periodic testing is necessary to ensure the long-term reliability and safety of the US arsenal.

Although Energy Secretary Chris Wright has clarified that any future tests would not involve nuclear explosions, President Donald Trump previously suggested that the United States could resume testing if other countries did so first. Yeaw echoed this sentiment, noting that any US action would be on an “equal basis” and in response to prior developments by China or Russia.

Meanwhile, Secretary of State Marco Rubio recently stated that the United States is exploring all diplomatic avenues to achieve Trump’s stated goal of reducing global nuclear weapons. However, Rubio also warned that Washington would not accept unchecked nuclear expansion by Moscow or Beijing.

According to US estimates, China has increased its nuclear stockpile from roughly the low 200s in 2020 to more than 600 warheads and could surpass 1,000 by 2030 if current growth continues.

US Calls for Multilateral Engagement

At the Geneva conference, Yeaw urged participating nations to encourage China and Russia to engage meaningfully in multilateral nuclear disarmament talks. The Conference on Disarmament brings together approximately 65 countries to discuss issues related to nuclear, biological, and chemical weapons control.

Washington has expressed openness to bilateral discussions, small-group negotiations, or broader multilateral frameworks aimed at restoring transparency and reducing global nuclear risks.

As geopolitical tensions rise and formal arms control mechanisms weaken, the unfolding dispute highlights the fragile state of global nuclear governance. Whether through renewed negotiations or heightened strategic competition, the coming years could significantly reshape the balance of nuclear power worldwide.