A US fighter jet shot down an unidentified “high-altitude object” over Alaska on Friday merely six days after downing a Chinese spy balloon that has triggered fresh tensions with Beijing.

White House National Security Council spokesman John Kirby said it was unclear what the purpose or origin of the new object was, but said that it was taken down because, floating at 40,000 feet, it posed a threat to the safety of civilian flights.

It went down in northern Alaska near the Canadian border and fell over a frozen body of water, making recovery of the debris feasible, Kirby said.

“Out of the recommendation of the Pentagon, President Biden ordered the military to down the object,” he added.

However, he declined to identify the object’s country of origin.

“We’re calling this an object because that’s the best description we have right now,” Kirby said. “We do not know who owns it, whether it’s state-owned or corporate-owned or privately-owned. We just don’t know.”

Kirby said the object was much smaller than a huge Chinese balloon that crossed the United States last week and was shot down by a US fighter jet off the Atlantic coast on Saturday.

“It was roughly the size of a small car,” he said. The Chinese balloon shot down earlier had been estimated to be the size of three buses.

Pentagon spokesman Brigadier General Pat Ryder said an F-22 Raptor used an AIM-9X missile to bring down the object which was also used to destroy the Chinese spy balloon.

The incident took place amid concerns of China flying surveillance balloons to collect intelligence around the world.

US officials said such balloons have flown over 40 countries including India and Japan.

The Chinese balloon last week sparked particular concern as it overflew areas where the United States keeps weapons sites and strategic military bases.

US Secretary of State Antony Blinken had cancelled his scheduled trip to Beijing at the last minute due to the incident.