Corrected 5:05 p.m. | Key appropriators who oversee the Pentagon’s budget urged the Biden administration on Tuesday to take more “decisive” action to address threats like the Chinese surveillance balloon that traversed the country in February. 

In a bipartisan letter to the White House obtained by CQ Roll Call, Senate Defense Appropriations Chairman Jon Tester, D-Mont., and ranking member Susan Collins, R-Maine, said the U.S. needs to ramp up its capabilities to combat similar incursions. 

“We remain deeply concerned by these violations of United States sovereignty, and it is clear more needs to be done to address these situations,” Tester and Collins wrote. 

The balloon, which had hovered over sensitive military sites in Tester’s home state, crossed the continental U.S. before being shot down by F-22 fighter jets off the coast of South Carolina. Its discovery and subsequent downing worsened already bad tensions with China and prompted widespread congressional calls for greater action to combat Chinese threats. 

While most Democrats defended President Joe Biden’s decision to take down the balloon over water, where falling debris could not harm people and property on the ground, Tester joined Republicans in condemning Biden’s actions. 

Tester and many GOP lawmakers criticized the Biden administration’s handling of the balloon, instead arguing it should have been shot down over the sparsely populated Aleutian Islands in Alaska before it had the chance to cross the country. 

“Quite frankly, I’ll just tell you, I don’t want a damn balloon going across the United States, when we potentially could have taken it down over the Aleutian Islands,” Tester said at a subcommittee hearing on Feb. 9. 

Many unanswered questions remain over the military’s system for detecting and addressing surveillance balloons. Multiple Chinese balloons had previously been detected in U.S. airspace prior to the one shot down, officials have said, though none spent as long a period of time floating above the country. And the circumstances surrounding the shoot down of three subsequent flying objects — which defense officials have said were apparently not Chinese assets — the weekend after remain even murkier. 

Pentagon spokesman Air Force Brig. Gen. Patrick Ryder told reporters earlier this month that U.S. commanders have benefited from a “continuing body of knowledge” about the Chinese spy balloons and are “very confident” they can detect any future ones near U.S. shores.

In their letter, Tester and Collins said they were “encouraged” to hear that the Biden administration will request added resources to tackle similar provocations in its fiscal 2024 budget request, which is due to arrive on March 9. 

“While questions remain regarding that highly publicized event, the Administration needs to strengthen our capabilities in this space,” the senators wrote. “There is no duty more important than keeping the United States safe and defending our national security. We will work with, and hold accountable, anyone to meet that responsibility.”

This report was corrected to reflect the passage of a Chinese balloon over the U.S. in February.

Briana Reilly contributed to this report.