China says US flew high-altitude balloons over its airspace

China said on Monday that US high altitude balloons had flown over its airspace without permission more than 10 times since the beginning of 2022, drawing a swift denial from Washington.

China's accusation widened a dispute with United States that began last weekend after the US military shot down what it says was a Chinese spy balloon, prompting top US diplomat Antony Blinken to cancel a trip to Beijing designed to ease tensions.

"Since last year, the US's high-altitude balloons have undergone more than 10 illegal flights into Chinese airspace without the approval of the relevant Chinese departments," Chinese foreign ministry spokesperson Wang Wenbin said at a regular briefing in Beijing in response to a question.

Wang did not specifically describe the balloons as military or for espionage purposes and did not provide further details.

Asked how China had responded to such incursions, Wang said its responses had been "responsible and professional".

White House national security spokesman John Kirby denied China's accusation.

"Not true. Not doing it. Just absolutely not true," he said in an interview with MSNBC. "We are not flying balloons over China."

The US Defense Department did not immediately respond to a request for comment.

China's assertion comes after the United States shot down what it called a Chinese surveillance balloon off the coast of South Carolina on 4 Feb after it had drifted across the continental United States for days.

China said the balloon was a civilian research craft that had mistakenly blown off course and accused the United States of overreacting.

In recent days, the US military has shot down three other flying objects over North America, most recently on Sunday, when an octagonal object was downed over Lake Huron, the Pentagon said.

Wang said he had no information on the latest three objects shot down by the United States.