A suspected Chinese spy balloon has been flying over the United States for a few days, and senior US officials have advised President Joe Biden against shooting it down for fear the debris could pose a safety threat.
"Clearly the intent of this balloon is for surveillance," a senior US defence official told reporters on Thursday.
China and the United States, the world's two largest economies, have experienced tensions of late, clashing over Taiwan and China's human rights record and its military activity in the South China Sea.
Washington has been tracking the balloon since it entered US airspace a couple of days ago, including by observing it with manned US military aircraft.
Officials declined to say how high the balloon was flying but acknowledged it was operating above civilian air traffic and below "outer space."
Senior US military leaders considered shooting down the balloon over Montana but eventually recommended against it because of the potential safety risk from debris.
US officials brought up the issue with their Chinese counterparts.
"We have communicated to them the seriousness with which we take this issue," the official added.
Spy balloons have flown over the United States several times in recent years, but this balloon appeared to be lingering longer than in previous instances, the official said.
"Currently, we assess that this balloon has limited additive value from an intelligence collection perspective, but we are taking steps nevertheless to protect against foreign intelligence collection of sensitive information," the official said. - Reuters