The Chinese Foreign Ministry on Thursday rubbished the US' accusation that China may have secretly conducted nuclear tests, and a Chinese nuclear disarmament expert said the groundless accusation is a US attempt to push China into a Western countries-led nuclear treaty while also diverting domestic pressures caused by the novel coronavirus.

The Chinese statements came after the US State Department on Wednesday released the Executive Summary of 2020 Adherence to and Compliance with Arms Control, Nonproliferation, and Disarmament Agreements and Commitments, which claimed that China may have secretly conducted low-level nuclear test blasts at the Lop Nur nuclear weapons test site throughout 2019.

The report did not provide evidence for what it claimed to be "zero yield" nuclear test blasts, Reuters reported on Thursday.

The US' accusation is completely groundless, fictitious and not even worth refuting, Foreign Ministry spokesperson Zhao Lijian said at a regular press conference held on Thursday.

Zhao said that China had been among the first countries to sign the Comprehensive Nuclear Test Ban Treaty, and China always supported the aim and purpose of the treaty, kept its promise of suspending nuclear tests, and made important contributions to the work of the treaty's Preparatory Commission.

Zhao noted that the technical secretariat of the Preparatory Commission had given full affirmation to the data transmission work of observation stations in China.

The US side ignored facts and made groundless speculation, and its accusation against China is irresponsible and reflects ulterior motives, Zhao said.

Citing the US State Department report, the Wall Street Journal claimed on Wednesday that China had used special chambers to contain explosions, and that data transmissions from monitoring stations that were designed to detect radioactive emissions and seismic tremors recorded interruptions in past years, and a satellite photo taken on March 29 of Lop Nur showed cement truck activity.

Yang Chengjun, a Chinese expert on missile technology and nuclear strategy, told the Global Times on Thursday that the Lop Nur test site was built in the early 1960s, and more than half a century had passed, so it is normal that there would be construction machinery undertaking maintenance work.

No special chamber could completely seal off a nuclear test blast, and radioactive materials are bound to leak to some extent and cause local earthquakes, Yang said, noting that China did not undertake any "coverups" of observation data, and the data transmission interruption could have been caused by system upgrades.

The US should reflect on itself in terms of arms control and in the nonproliferation field, as it had prioritized its own interests by quitting multiple related treaties and going against the trend of the times, Zhao said.

"Quitting the Intermediate-Range Nuclear Forces Treaty and the Joint Comprehensive Plan of Action with Iran, withdrawing from the signing of the Arms Trade Treaty, obstructing negotiations for a protocol with a verification regime of the Biological Weapons Convention, having still not disposed of all stockpiles of chemical weapons, enhancing military power in all aspects … the US has seriously sabotaged the global strategic balance and stability, hindered international arms control and disarmament, and drawn general condemnation from the international community. It has no right to see itself as a referee or judge," Zhao said.

Yang said that the US has been trying to tie China down in a Western countries-led nuclear arms control arrangement, but China should not participate because the US possesses far more nuclear weapons than China, and the US has never stopped developing nuclear weapons.

By asking China to join the arrangement and seeing China refuse to do so, the US is also hoping to gain a public opinion advantage for itself to further make tactical, low-yield nuclear weapons, which the US has already developed and deployed on its missiles, Yang said.

Hyping groundless speculation about China conducting nuclear tests could also be an attempt to shift domestic focus, as the US is under huge pressure from the COVID-19 epidemic with more than 630,000 Americans infected, Yang said.