US official told reporters the military was prepared to shoot the balloon down but was deterred by potential for harm.
A senior defence official told Pentagon reporters on Thursday the US has “very high confidence” it is a Chinese high-altitude balloon and that it was flying over sensitive sites to collect information.
One of the places the balloon was spotted was Montana, which is home to one of the nation’s three nuclear missile silo fields at Malmstrom Air Force Base. The official spoke on condition of anonymity to discuss sensitive information.
Brigadier General Patrick Ryder, the Pentagon press secretary, provided a brief statement on the issue, saying the government continues to track the balloon. He said it is “currently travelling at an altitude well above commercial air traffic and does not present a military or physical threat to people on the ground”.
He said similar surveillance activity has been seen in the past several years, adding that the US had taken steps to ensure the balloon did not collect sensitive information.
The defence official said the US has “engaged” Chinese officials through multiple channels and communicated the seriousness of the matter.
The Pentagon announcement comes days before US Secretary of State Antony Blinken is expected to travel to China. It is not clear if this will affect his travel plans, which the State Department has not formally announced.
The US is expanding its military presence in Asia in a string of moves aimed at countering Beijing and reassuring Indo-Pacific allies it will stand with them against threats from China and North Korea.
The senior defence official said the US did get fighter jets, including F-22s, ready to shoot down the balloon if ordered to by the White House. The Pentagon ultimately recommended against it, noting that even though the balloon was over a sparsely populated area of Montana, its size would create a debris field large enough to potentially put people at risk.
The official would not specify the size of the balloon but said it was large enough that, despite its high altitude, commercial pilots could see it.
The official said what concerned them about this launch was the altitude the balloon was flying at and the length of time it lingered over a location, without providing specifics.