HONG KONG — China urged calm Friday and said it was investigating reports of a high-altitude surveillance balloon suspected of belonging to Beijing flying over the United States, while Canada said it was monitoring a «potential second incident.»

US officials said Thursday the military was monitoring the balloon, which flew over the Aleutian Islands and across Canada before being seen Wednesday over Billings, Montana. A senior defense official said the United States was confident the balloon belonged to China, which has flown stratospheric balloons over the country before, but not for as long.

Chinese Foreign Ministry spokesman Mao Ning said Beijing was assessing the situation and speculation and exaggeration did not help while the facts were cleared up.

«China is a responsible country that always abides by international law and has no intention of infringing on any country’s territory or airspace,» Mao told a daily briefing.

«We hope that both parties can handle this together calmly and carefully,» he added.

The balloon reveal comes days before Secretary of State Antony Blinken is scheduled to visit China, the highest-ranking Biden administration official to do so. Mao said he had no information on whether his visit would be affected.

in a short statement On Thursday night, Canada’s Department of National Defense said a high-altitude surveillance balloon had been detected and that the North American Aerospace Defense Command, a US-Canadian military organization, was «actively tracking it.» He did not provide details about the balloon or say if it was the same balloon detected in the US.

«Canadians are safe and Canada is taking steps to ensure the safety of its airspace, including monitoring for a possible second incident,» he said, without elaborating.

The statement, which did not mention China, added that Canadian intelligence agencies were working with American partners to protect against «foreign intelligence threats.»

The department did not immediately respond to phone calls and emails requesting additional information.

The senior defense official said Thursday that the balloon was still over the United States, but declined to say where. So far it has not been shot from the sky, US officials said, because falling debris could pose a safety risk to people on the ground. They said the balloon had limited use for intelligence gathering and did not pose a threat to civil aviation.

Chinese experts raised questions about the globe’s origin in an article published Friday in The Global Times, a state-backed nationalist tabloid. Liu Ming, director of the scientific and technological intelligence company MizarVision, said images released by US officials appeared to show a balloon unable to travel such long distances or with such precision.

Military expert Zhang Xuefeng told the newspaper that the US would not necessarily be able to identify the country of origin of the balloon while it was still in the sky, and that it made no sense for China to use balloons to spy on the mainland US when it has a much more effective satellite network.

“It is recommended that the United States shoot down the balloon and find some clues before blaming other countries,” Zhang said.

isaac lee, courtney kube, Carol E. read and wang yixin contributed.