(NewsNation) — For the second time in a week, the U.S. military shot down a “high altitude” object — this time over frozen waters off the northeastern coast of Alaska, according to White House National Security Council spokesperson John Kirby. Just days earlier, a suspected Chinese surveillance balloon was brought down off the coast of South Carolina.

Kirby said the U.S. learned of an object flying at about 40,000 feet last evening over Alaska airspace. The Pentagon recommended to President Joe Biden that the object should be shot down as it posed a “reasonable threat to the safety of civilian flight,” he said.

It was unclear to U.S. officials who was behind the newly-downed object, Kirby said in response to a question from NewsNation’s chief Washington correspondent Blake Burman.

He described the object as being the “size of a small car” that was not “self-maneuvering” and said the debris field is expected to be smaller than that of the balloon. Comparing the two situations was like “apples to oranges,” he said, but that there was little information available about the object including whether it had surveillance equipment on it.

“We are going to remain vigilant about our airspace. The safety of the American people is paramount,” Kirby said.

The U.S. deployed two fighter jets to surveil the object Thursday and determined it was unmanned, Kirby said. Then, the president gave the order, and at 1:45 p.m. ET Friday, an F-22 shot an AIM-9 Sidewinder short-range air-to-air missile to take down the object, according to Defense Department spokesman Brigadier General Pat Ryder.

“We are going to judge each of these objects on its own merit,” he said.

The surveillance balloon brought down just days ago had also charted a path over Alaska and other states before being brought down over the waters near South Carolina.

The Biden administration faced sharp criticism from lawmakers over how the incident was handled. Among the critics was Sen. Lisa Murkowski (R-Alaska) who told reporters Thursday that she felt her state was “treated differently” because it is not part of the continental U.S.

“No state should feel like they are more vulnerable than the rest,” she said. Alaska “is standing as the first line of defense for the United States of America, when things are coming across from China or Russia, let us be that line of defense for the rest of the country,” she added.

Burman asked Kirby if the new U.S. policy was to shoot down objects over water and he replied that a policy cannot be derived from a situation that has occurred twice.

This is a developing story. Please check back for updates