CHINA - The American flag was lowered at the US consulate in Chengdu on Monday and Chinese authorities entered the building as Beijing carried out a Cold War-style retaliatory closure of the mission.

Relations have deteriorated in recent weeks in an intensifying standoff between Washington and Beijing, with the Chengdu mission ordered to shut in retaliation for the forced closure of the Chinese consulate in Houston, Texas.

Beijing confirmed that the consulate had closed at 10:00 am (0200 GMT) on Monday. "Afterwards, Chinese authorities entered through the front entrance and took it over," the foreign ministry said in a statement. Both consulates closed 72 hours after the respective orders were made.

A State Department spokesman told AFP the mission's diplomats and their dependents would leave China by August 27. Video footage published later Monday by the US embassy on Chinese social media platform Weibo showed US Marines in dress uniform lowering and folding the Stars and Stripes from the front of the consulate, before handing it to consul-general Jim Mullinax. Diplomatic tensions have soared between the two powers, with both alleging the other had endangered national security.