A White House official said the object was flying at about 40,000ft and posted a ‘reasonable threat’ to the safety of civilian flights.

A US fighter jet has shot down a high-altitude object over Alaska that was the size of a small car, the White House said on Friday.

White House National Security Council spokesman John Kirby told reporters the object was flying at about 40,000ft and posted a “reasonable threat” to the safety of civilian flights.

It was unclear where the object came from which was downed over frozen waters, Kirby said. “We don’t know who owns this object,” he said.

He said the object went down on the far northeastern part of Alaska near the Canadian border and pilots determined the object was not manned.

He added many details were unknown about the object but it is expected to be recovered after it landed in US territorial waters.

The object was shot down on the orders of US President Joe Biden, White House officials said.

Officials said in a statement: “Out of an abundance of caution and at the recommendation of the Pentagon, President Biden ordered the military to down the object over water.”

It comes after the US shot down an alleged Chinese “spy balloon” over its territorial waters off the coast of South Carolina, last Saturday (February 4).

Mr Kirby added that the object’s debris field was “much, much smaller” than the balloon shot down last week.