The United States on Tuesday ordered the suspension of all flights by Chinese airlines into and out of the country after Beijing failed to allow American carriers to resume services to China.

"US carriers have asked to resume passenger service, beginning June 1st. The Chinese government's failure to approve their requests is a violation of our Air Transport Agreement," the US Transportation Department (DoT) said in a statement.

The suspension order takes effect June 16, but could be implemented sooner if President Donald Trump orders it, the statement said.

US air carriers sharply reduced or suspended service to China amid the COVID-19 pandemic, but United and Delta submitted applications at the beginning of May to resume flights and have been unable to receive authorization from Civil Aviation Authority of China (CAAC), DoT said.

Coming at a time of heightened tensions between Washington and Beijing, the latest spat centers partially on the CAAC deciding to determine its limit on foreign airlines based on their activity on March 12.

But US carriers by then had suspended all flights due to the pandemic -- meaning their cap was calculated to be zero -- while Chinese-flagged flights continued.

The "arbitrary 'baseline' date... effectively precludes US carriers from reinstating scheduled passenger flights to and from China," the DoT order says.

The department also said there are indications Chinese airlines are using charter flights to get around the limit of one flight a week to increase the advantage over US carriers.

"Our overriding goal is not the perpetuation of this situation, but rather an improved environment wherein the carriers of both parties will be able to exercise fully their bilateral rights," DoT said in the order.

In early January 2020, before the pandemic struck, US and Chinese carriers operated approximately 325 weekly flights between the two countries.