WASHINGTON (Reuters) – The Pentagon is tracking a suspected Chinese spy balloon which has been flying over the United States, U.S. officials said on Thursday, a spy-movie like intelligence collection method that recalls the lengths to which Beijing and Washington are willing to go to spy on each other amid increased tensions.

“Clearly the intent of this balloon is for surveillance,” a senior U.S. defense official, speaking on the condition of anonymity, said.

The official said that Washington had been tracking the balloon since it entered U.S. airspace a couple of days ago, including by observing it with manned U.S. military aircraft.

Senior U.S. military leaders considered shooting down the spy balloon over Montana but eventually recommended against it because of the potential safety risk from debris.