• A U.S. fighter jet shot down a "high altitude object" off the coast of Alaska, less than a week after a high altitude Chinese surveillance balloon was shot down off the coast of South Carolina.
• White House spokesman John Kirby hesitated to characterize the aircraft as a balloon. "We're calling this an object because that's the best description we have right now," he said.
• The latest object was smaller than the spy balloon and flying at a lower altitude, which posed a threat to civilian aircraft, the White House said.

WASHINGTON — The U.S. military shot down a second "high altitude object" in American airspace, this time off the coast of Alaska on Friday, the White House announced.

The mission occurred less than a week after a high altitude Chinese surveillance balloon was shot down off the coast of South Carolina.

White House spokesman John Kirby hesitated to characterize the aircraft as a balloon, saying "we're calling this an object because that's the best description we have right now." He also said U.S. officials did not yet know which nation or group was responsible for it.

The object was destroyed by a missile from an F-22 fighter plane off the far northeastern coast of Alaska, Kirby said at a White House press briefing.

The U.S. military first became aware of the object on Thursday night. President Joe Biden gave the order to shoot it down on Friday morning, which was carried out shortly after noon.

The craft was flying at approximately 40,000 feet in altitude, which is lower than the balloon last week, and it was the size of a small car, he said.

Unlike the balloon shot down on Saturday, the latest object did not appear to possess any maneuverability, Kirby said.

Last week's spy balloon was the size of three school buses, according to Pentagon officials. A sophisticated surveillance craft with propellers that gave it maneuverability, the balloon carried a payload the size of a jetliner.

The latest incident also differed significantly from the prior one in that this floating object was shot down within hours of its detection.

The larger, previous balloon was permitted to float across the United States for a week before Biden gave the order to shoot it down.

The Pentagon defended that decision at a Senate hearing on Thursday, telling lawmakers that the spy balloon's primary value to the U.S. military lay in what could be learned from its flight course and its debris.

"A key part of the calculus for this operation was the ability to salvage, understand and exploit the capabilities of the high altitude balloon," said Assistant Secretary of Defense Melissa Dalton.

Another factor influencing the decision to let the previous balloon remain in the air was that it was floating at approximately 60,000 feet in altitude, where it did not pose an immediate threat to civilian aircraft. Commercial airliners typically cruise at an altitude of 35,000 feet.

The object shot down on Friday was floating at just 40,000 feet, however, creating what the White House called "a reasonable threat" to air safety.

A Pentagon spokesman said Friday that the salvage operation for the latest object was already underway, but had been hampered by rough seas in the Arctic Ocean that made diving especially perilous.