Washington: China is giving the US silent treatment ever since the US sent an F-22 Raptor to shoot down the Chinese spy balloon that navigated into North American airspace last week. This can be seen in US Defence Secretary Lloyd Austin's call to Beijing going unanswered, New York Post reported.

According to New York Post, the snub by China was the latest sign of frayed US communications with its great adversary, leading to fears that a relatively minor incident could spiral into something bigger.

US Secretary of State Antony Blinken had planned to reopen lines of communication with China during his trip to Beijing. The trip, however, got postponed after China's spy balloon intrusion became public.

Therefore, when the Pentagon asked to hold a secure call between Austin and his Chinese counterpart, Wei Fenghe, the answer was a "no".

The Chinese Ministry of Defence still refuses to admit that the balloon was conducting surveillance. The ministry said that Austin's call was declined because the US "seriously violated international practices and set a very bad precedent" by downing the device they claim was a "civilian unmanned airship" meant for scientific research that drifted off-course due to "force majeure".

"In view of the US side's irresponsible and seriously wrong practice, which had failed to create a proper atmosphere for dialogue and exchange between the two militaries, China didn't accept the US proposal for a phone call between the two defence chiefs," ministry spokesman Senior Col. Tan Kefei said on Thursday, according to New York Post.

The US intelligence community has linked the Chinese spy balloon to a vast surveillance program run by the People's Liberation Army, and US officials have begun to brief allies and partners who have been similarly targeted, The Washington Post reported.

According to The Washington Post, the surveillance balloon effort, which has operated for several years partly out of Hainan province off China's south coast, has collected information on military assets in countries and areas of emerging strategic interest to China including Japan, India, Vietnam, Taiwan and the Philippines, according to several US officials.

According to officials, the surveillance airships, operated partly by the PLA air force, have been spotted over five continents.

An official said: "What the Chinese have done is taken an unbelievably old technology, and basically married it with modern communications and observation capabilities to try to glean intelligence on other nations' militaries. It's a massive effort."

The New York Times recently reported that, as part of its response to a Chinese spy balloon that traversed US airspace last week, the Joe Biden administration on Friday (local time) clamped down on sales of some of its technology to several Chinese aviation and technology companies.