WASHINGTON, Feb 17 (GeokHub) — A senior U.S. official said on Tuesday that China may have conducted an underground nuclear test in June 2020, an allegation Beijing has dismissed as politically motivated.
Assistant Secretary of State Christopher Yeaw told an event at the Hudson Institute that a seismic station in Kazakhstan recorded an “explosion” of magnitude 2.75 on June 22, 2020, near the Lop Nor test site in western China.
“I’ve looked at additional data since then. There is very little possibility I would say that it is anything but an explosion, a singular explosion,” Yeaw said, adding the signals were inconsistent with mining activity or natural earthquakes. “It is … what you would expect with a nuclear explosive test.”
The Comprehensive Test Ban Treaty Organization (CTBTO), which monitors for nuclear test explosions worldwide, said the data were inconclusive. Its PS23 seismic station recorded two minor events spaced 12 seconds apart, which were too small to confirm a nuclear detonation.
A spokesperson for the Chinese embassy in Washington called the U.S. claim “entirely unfounded” and accused Washington of attempting “to fabricate excuses for resuming its own nuclear testing.” The spokesperson urged the U.S. to uphold the global non-proliferation framework and respect commitments under the Comprehensive Nuclear-Test-Ban Treaty.
President Donald Trump has been pressing China to join the U.S. and Russia in negotiating a successor to New START, the last strategic nuclear arms limitation treaty between Washington and Moscow, which expired on Feb. 5. Analysts warn that the expiration may accelerate a global nuclear arms race.
China, which has signed but not ratified the 1996 test ban treaty, has previously denied conducting nuclear tests since its last official detonation in 1996. Yeaw suggested that China may have attempted to conceal the alleged 2020 test through a technique called decoupling, which reduces the seismic signature of underground explosions.
The Pentagon estimates that China currently possesses more than 600 operational nuclear warheads and is expanding its strategic arsenal, projecting a stockpile exceeding 1,000 warheads by 2030. By contrast, the U.S. has relied on advanced simulations instead of underground tests since 1992 to maintain the reliability of its nuclear weapons.
