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 US 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 Y Carol E. read contributed.