The Defense Department’s plan to remove Air Force fighters from Okinawa sends the wrong signal to China and U.S. allies in the region, according to prominent Republicans in Congress seeking more information about the decision.

The lawmakers wrote to Secretary of Defense Lloyd Austin on Tuesday asking to be briefed about a plan the Air Force announced Friday to replace two F-15 squadrons with rotational forces.

In their letter, Sen. Marco Rubio of Florida; Rep. Mike Gallagher of Wisconsin, the top Republican on the Armed Services personnel subcommittee; Sen. Bill Hagerty of Tennessee, the former ambassador to Japan; and Rep. Mike McCaul of Texas, the top Republican on the Foreign Affairs Committee, expressed concerns about the message that the move sends.

“We are concerned that DOD’s decision sends the wrong signal, not only to the [Chinese Communist Party], but also to our allies and partners in the Indo-Pacific,” the group wrote.

The Air Force confirmed plans for a two-year “phased withdrawal” starting this week of F-15C/D Eagles deployed to Kadena Air Base, Okinawa. The Eagles are to be replaced initially by fifth-generation F-22 Raptors in six-month rotations from Alaska.

The lawmakers’ concerns echo those expressed by experts immediately after the announcement.

“The message to China is the U.S. is not serious about reversing the decline in its military forces,” David Deptula, former vice commander of Pacific Air Forces and a retired F-15 pilot, told the Financial Times newspaper for a report Oct. 27. “This will encourage the Chinese to take more dramatic action.”

A permanent contingent of Air Force fifth-generation fighters west of the International Date Line is a “desirable” option as the U.S. seeks to deter an increasingly assertive China, the head of U.S. Indo-Pacific Command, Adm. John Aquilino, told the Foundation for Defense of Democracies think tank in June.

Kadena is home to 48 F-15C/Ds of the 18th Wing’s 44th Fighter Squadron and the 67th Fighter Squadron. The Air Force also has F-16 Fighting Falcons at Misawa Air Base in northeastern Honshu, the largest of Japan’s four main islands.

The F-15, built by McDonnell Douglas, has an unmatched record of 104 kills and zero losses since it entered service in 1976. The Eagle can travel 1,875 mph, more than twice the speed of sound, according to the Air Force’s official website.

“While we agree with the need to modernize the Air Force’s fleet in order to counter the rising threat of the [Chinese army], we are concerned with reporting that indicates that there will be no permanent presence to replace the Okinawa F-15s,” the lawmakers wrote.

They asked Austin to brief them about “steps to replace the deterrent value and combat capability of any assets removed from the Indo-Pacific region as well as the administration’s plan to establish a force posture in the Indo-Pacific that would be resilient to a [Chinese] attack and capable of deterring an invasion of Taiwan.”

Plans to replace permanently based fighters with rotational forces will “lead to a tangible reduction in American forward combat power in the Indo-Pacific, lowering the bar for aggression and demonstrating a continuing mismatch between the Biden Administration’s talking points on the Indo-Pacific and America’s actual commitments in the region,” the lawmakers wrote.