China Rejects U.S. Allegation of Secret Nuclear Explosion

A senior United States official has disclosed what he described as fresh intelligence suggesting that China may have conducted an underground nuclear test in June 2020.

Speaking on Tuesday at an event hosted by the Hudson Institute in Washington, Assistant Secretary of State Christopher Yeaw said seismic readings from a monitoring station in Kazakhstan detected a magnitude 2.75 explosive event approximately 450 miles (720 kilometers) from China’s Lop Nor nuclear testing site in the country’s western region.

According to Yeaw, further analysis of the data indicates the seismic activity was consistent with an explosion rather than natural causes or routine industrial activity. He stated that the signal did not match the pattern of an earthquake or a mining blast but instead resembled what would typically be expected from a nuclear detonation. Yeaw, a former intelligence and defence official with a doctorate in nuclear engineering, maintained that the likelihood of it being anything other than an explosion was minimal.

However, the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), the global body responsible for tracking nuclear test explosions, said the available data was insufficient to conclusively verify the allegation.

China swiftly rejected the accusation. A spokesperson for the Chinese Embassy in Washington described the claim as baseless and politically motivated, suggesting it was aimed at justifying a potential resumption of U.S. nuclear testing.

In a written statement, embassy spokesperson Liu Pengyu accused Washington of attempting to undermine global nuclear disarmament efforts while pursuing what he called “nuclear hegemony.” He urged the United States to recommit to the pledge made by the five recognized nuclear-weapon states to refrain from conducting nuclear tests and to take meaningful steps toward strengthening international non-proliferation frameworks.

The controversy comes amid rising tensions over global arms control. U.S. President Donald Trump has been advocating for China to participate in negotiations alongside the United States and Russia to replace New Strategic Arms Reduction Treaty (New START) — the last remaining strategic nuclear arms reduction agreement between Washington and Moscow, which expired on February 5.

The lapse of the treaty has heightened fears among analysts that the world could be entering a renewed and potentially accelerated nuclear arms race.

China, which signed but has not ratified the 1996 Comprehensive Nuclear-Test-Ban Treaty, insists it has not carried out any nuclear test explosions since its last acknowledged underground test in 1996.