WASHINGTON: A US military fighter jet shot down an unknown object flying off the remote northern coast of Alaska on Friday on orders from President Joe Biden, White House officials said.

White House National Security Council spokesman John Kirby said the object was downed because it was flying at about 40,000 feet (13,000 meters) and posed a 'reasonable threat' to the safety of civilian flights, not because of any knowledge that it was engaged in surveillance. Asked about the object's downing, Biden on Friday said only that 'It was a success.'