U.S. offers more details on claim China conducted secret nuclear test - The Washington Post

[Key Wu]

https://www.washingtonpost.com/national-security/2026/02/17/china-nuclear-test-trump/

U.S. offers more details on claim China conducted secret nuclear weapons test

Remarks by a top administration official appeared to be aimed at dispelling skepticism of its assertions, as President Donald Trump vows to restart U.S. tests.

Cate Cadell

February 17, 2026 at 4:44 p.m. ESTYesterday at 4:44 p.m. EST

A top Trump administration official on Tuesday disclosed new details to support its claim that China conducted an underground nuclear explosion during Donald Trump’s first presidency, a contested assertion that, nevertheless, has become a catalyst for his push to resume such testing by the United States.

“We’re not going to remain at an intolerable disadvantage,” Christopher Yeaw, who heads the State Department’s Bureau of Arms Control and Nonproliferation, said during a discussion at the Hudson Institute, a think tank in Washington. He urged Beijing to “come clean” about its nuclear weapons tests, which some U.S. officials and experts say is part of a determined Chinese effort to catch up to, if not eclipse, the United States’ global advantage in nuclear weapons technology.

The event in question occurred June 22, 2020, “right near” a secretive facility known as Lop Nur in China’s western Xinjiang region, Yeaw told those attending the discussion. The U.S., he added, used seismic data captured by a facility in neighboring Kazakhstan to conclude that China had conducted an explosive nuclear test.

The activity — measured at a magnitude of 2.76 — was not consistent with an earthquake or explosions used in mining, Yeaw said. The suspected explosion’s yield — meaning the amount of energy it released — remains unclear because of the Chinese government’s efforts to conceal the test, he said, adding, “We know that they were preparing designated tests of hundreds of tons” in yield.