On Friday the Biden Administration's Department of Transportation announced that it is suspending 44 flights from the US to China on Chinese carriers in response to China's suspension of US to Shanghai flights on US carriers under China's COVID-19 protocols.

Chinese carriers the flights of which have been suspended between 30 January and 29 March include Air China, China Eastern, China Southern and Xiamen Airlines.

China has a "circuit breaker" policy under which airline routes can be shut down if too many inbound passengers are found to test positive for COVID-19.

US DOT said in a statement:

"US carriers, who are following all relevant Chinese regulations with respect to pre-departure and in-flight protocols, should not be penalized if passengers, post-arrival, later test positive for COVID-19."

Beijing has suspended thousands of inbound flights since the city's first case of the Omicron variant was discovered last week. The Chinese government has claimed a package airshipped from Canada brought the virus - an allegation which the government of Canada dismisses as absurd.

The Beijing 2022 Winter Olympics are scheduled to begin next month. Because of the risk of COVID-19, Olympic organizers have stopped all ticket sales and have said that they will instead be inviting selected attendees.