US Assistant Secretary of State Christopher Yeo said during an event at the Hudson Institute think tank in Washington that China conducted an underground nuclear test in 2020, Reuters reported, News.bg reports.
According to him, a remote seismic station in Kazakhstan registered an explosion with a magnitude of 2.75 on June 22, 2020. The event was located about 720 kilometers from the Lop Nor test site in western China.
Yeo indicated that subsequent analysis of the data showed “very low probability” that the phenomenon was anything other than a single explosion. According to him, the characteristics of the signal are not consistent with either mining activities or a natural earthquake. "This is what you would expect from a nuclear explosion," he stressed.
The Comprehensive Nuclear-Test-Ban Treaty Organization said that the available data was not sufficient to confirm such a claim with confidence.
The spokesman for the Chinese Embassy in Washington, Liu Pengyu, described the accusations as "completely groundless" and described them as an attempt to find justification for a possible resumption of nuclear tests by the United States. According to him, this is a political manipulation aimed at achieving nuclear superiority and deviating from disarmament commitments.
Pengyu called on the United States to refrain from nuclear tests and to reaffirm the commitment of the five nuclear powers to the global consensus against such actions, as well as to take concrete steps to support the international non-proliferation and disarmament regime.
At the same time, US President Donald Trump insisted that China join the US and Russia in negotiations on a new treaty to replace New START - the last agreement between Washington and Moscow to limit strategic nuclear weapons, which expired on February 5. Its leak has heightened fears of a new arms race.
China, however, has rejected the proposal for trilateral talks, arguing that its strategic nuclear arsenal is significantly smaller than that of the United States and Russia.
According to Pentagon data, China has more than 600 operational warheads and is expanding its strategic nuclear forces, with projections indicating that their number could exceed 1,000 by 2030.
China has signed but not ratified the 1996 Comprehensive Nuclear-Test-Ban Treaty. After the United States raised the accusation earlier this month at an international conference, Beijing again denied conducting an underground test. The last officially announced one by the country dates back to 1996.
The PS23 seismic station in Kazakhstan is part of the Comprehensive Nuclear-Test-Ban Treaty Organization's global monitoring system. The organization's Executive Secretary, Robert Floyd, announced that on June 22, 2020, the station registered two small seismic events with an interval of 12 seconds.
According to him, the system can detect explosions equivalent to at least 500 metric tons of TNT. However, the registered events were significantly below this threshold, which does not allow for a clear determination of their cause based on the available data alone.
Christopher Yeo also stated that, according to the US side, China may have used a technique known as “decoupling“ - a method in which the device is detonated in a large underground chamber in order to limit seismic waves and conceal the real power of the explosion.