Sen. Lisa Murkowski (R-Alaska) said the U.S. needs to send a “clear and unequivocable” message that it will not tolerate incursions into its airspace, after a second “high-altitude object” was shot down over Alaska on Friday.

“The first line of defense, again, is Alaska,” Murkowski said in an interview with NBC News on Friday. “If it comes into Alaska airspace, if it comes over Alaska waters, we need to act. We need to send the message and we need to be clear and unequivocable that we don’t tolerate this, period.”

The object was traveling over Alaska at around 40,000 feet and posed “a reasonable threat to the safety of civilian flight,” White House national security spokesman John Kirby said. It was shot down on Friday afternoon and landed in U.S. waters, he added.

The government is still collecting information on the object and does not know whether it was operated by another country or if it was privately or commercially owned, Kirby also noted.

The “high-altitude object” is the second of its kind to travel into U.S. airspace in recent weeks, after a suspected Chinese spy balloon traversed the country earlier this month. 

The Chinese balloon, which Beijing has claimed was a weather balloon blown off course, crossed into U.S. airspace over Alaska on Jan. 28. After briefly crossing through Canadian airspace, the balloon reentered U.S. airspace through Idaho on Jan. 31.

Amid safety concerns about shooting the balloon down over land, the U.S. military waited until it reached open water off the coast of South Carolina last Saturday to take down the balloon.

Republicans, including Murkowski, have widely criticized President Biden’s handling of the original balloon incident, particularly the decision to wait to shoot it down.

“As an Alaskan, I am so angry. I want to use other words, but I’m not going to,” Murkowski said at a Senate Appropriations subcommittee hearing with defense officials on Thursday. 

“The fact of the matter is, Alaska is the first line of defense for America, right?” she continued. “If you’re going to have Russia coming at you, if you’re going to have China coming at you, we know exactly how they come. They come up and they go over Alaska.”

“Seems to me the clear message to China is ‘we’ve got free range in Alaska, because they’re going to let us cruise over that,’” Murkowski added.