WASHINGTON >> The U.S. is tracking a suspected Chinese surveillance balloon that has been spotted over U.S. airspace for a couple days, but the Pentagon decided not to shoot it down due to risks of harm for people on the ground, officials said today.

A senior defense official told Pentagon reporters that the U.S. has “very high confidence” it is a Chinese high-altitude balloon and 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.

Brig. Gen. Patrick Ryder, Pentagon press secretary, provided a brief statement on the issue, saying the government continues to track the balloon. He said it is “currently traveling 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 balloon activity has been seen in the past several years. He added that the U.S. took steps to ensure it did not collect sensitive information.

The defense official said the U.S. has “engaged” Chinese officials through multiple channels and communicated the seriousness of the matter.

The Pentagon announcement comes days before Secretary of State Antony Blinken is expected to travel to China. It’s not clear if this will affect his travel plans, which the State Department has not formally announced.