U.S. alleges Chinese nuclear test and urges nations to press for disarmament

A U.S. arms control official presented declassified material alleging a 2020 underground nuclear explosion at China’s Lop Nur site and urged nations to press China and Russia on disarmament; China denied the accusation and the New START treaty recently expired.

A U.S. arms control official spoke at a U.N.-backed disarmament conference and presented what he described as new, declassified details about an alleged underground nuclear explosion in China in June 2020. The comments came as the New START treaty between the United States and Russia recently expired, removing formal limits on their arsenals. The U.S. official urged other countries to press China and Russia for greater transparency on nuclear weapons. China rejected the accusations and said it has adhered to its testing commitments. Key facts: - A U.S. assistant secretary for arms control cited declassified details and seismic data reported as indicating a probable underground explosion at the Lop Nur site on June 22, 2020. - China’s ambassador to the conference publicly denied the accusation and said Beijing rejects the claims as unfounded, according to the article. - The New START treaty between the United States and Russia expired this month, which the article notes has ended formal limits on their nuclear arsenals. - The U.S. official met with a Russian delegation and was scheduled to meet Chinese and other delegations in Geneva, per the report. Summary: The U.S. allegation draws renewed attention to nuclear transparency and differing accounts between Washington and Beijing. Diplomatic meetings in Geneva involving U.S., Russian and Chinese delegations were reported as the immediate next steps.