There are concerns about surveillance and intelligence gathering being done via the balloon, and authorities working to protect US national security have advised against taking “kinetic action” against the spycraft because of the danger of debris falling to the ground.

The United States is tracking a suspected Chinese surveillance balloon that has been spotted hovering over the northern US earlier this week, a senior defence official said Thursday.

The US government “has detected and is tracking a high-altitude surveillance balloon that is over the continental United States right now”, Pentagon spokesman Brig. Gen. Patrick Ryder also said in a statement Thursday.

“We are confident that this high-altitude surveillance balloon belongs to the [People’s Republic of China],” the senior defence official said, speaking on condition of anonymity. “Instances of this activity have been observed over the past several years, including prior to this administration.”

“The balloon 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,” Ryder said. “Once the balloon was detected, the US government acted immediately to protect against the collection of sensitive information.”

US military leaders have for now decided against shooting the balloon down “due to the risk to safety and security of people on the ground from the possible debris field”.

The balloon was spotted on the Canadian border earlier in the week. It later entered US airspace in Montana, the sparsely populated western US state that is home to a nuclear missile base, on Wednesday.

The Pentagon added that US military leaders including Defence Secretary Lloyd Austin and General Mark Milley, the chairman of the US Joint Chiefs of Staff, met on Wednesday to assess the threat.

Pentagon officials declined to disclose the aircraft’s current location during Thursday’s briefing. They also refused to provide more details of the object, including its size.

US national security officials have constantly warned about China’s espionage efforts, and the balloon’s presence in the US comes at a sensitive time when Washington and Beijing have begun to warm up to economic talks and members of US President Joe Biden’s administration are preparing for trips to China in the coming weeks.

It comes ahead of US Secretary of State Antony Blinken’s visit to Beijing, a significant trip meant to follow up on Biden’s meeting with Chinese President Xi Jinping last year.

Blinken, who will be the highest-level US diplomat to meet Xi in China in about six years, will hold talks with the Chinese leader on a wide range of issues, including security, Taiwan, and Covid-19.