The Trump administration has told Congress that its position on Turkey’s possible return to the F-35 fighter jet program remains unchanged, emphasizing that existing United States law continues to bar Ankara from acquiring the aircraft as long as it retains the Russian made S-400 air defense system.
In a written response to lawmakers, the State Department said it remains fully committed to enforcing the Countering America’s Adversaries Through Sanctions Act (CAATSA), which restricts defense cooperation with countries that purchase certain Russian military systems.
Turkey was removed from the F-35 program after it acquired the S-400, a decision Washington has repeatedly said is incompatible with NATO security requirements.
The response was sent by Paul Guaglianone, a senior official in the State Department’s Office of Legislative Affairs, to Representative Chris Pappas and 19 other members of Congress who had written to Secretary of State Marco Rubio on September 25.
Their letter followed media reports suggesting that discussions between Washington and Ankara on Turkey’s reintegration into the F-35 program were progressing, raising concerns on Capitol Hill about a potential sale of F-35 and F-16 fighter jets to Turkey.
According to the State Department, the Turkish government has been formally informed of the current legal and policy framework governing the acquisition of Russian defense equipment and the consequences this carries for access to advanced United States military platforms.
The department reiterated that the requirements set out in the National Defense Authorization Act and under CAATSA remain binding, and that Washington’s opposition to Turkey’s purchase of the S-400 system has been clearly communicated.
The letter also underscored respect for Congress’s oversight role in arms transfers, noting that the administration welcomes continued dialogue with lawmakers as it seeks to balance NATO readiness with the constraints imposed by United States law and policy.
On the separate issue of F-16 aircraft, the State Department said the proposed sale was formally notified to Congress in January 2024 under the Arms Export Control Act and that the statutory review period was completed within the same month.
Turkey operates the second largest fleet of F-16 fighter jets in NATO after the United States, and administration officials have argued that modernizing that fleet supports the alliance’s collective air defense.
The department described the United States Turkey defense relationship as important to the security interests of both Washington and NATO, pointing to Turkey’s recent contributions to alliance missions.
These include the deployment of F-16 aircraft for NATO air surveillance in the Baltic region and the use of a Turkish airborne early warning aircraft in Lithuania following a Russian violation of Lithuanian airspace.
At the same time, senior United States officials have acknowledged that diplomatic engagement with Ankara continues alongside the firm legal framework.
In late June, Tom Barrack, the United States ambassador to Turkey, said there was a realistic opportunity to resolve the long running dispute over Turkey’s exclusion from the F-35 program by the end of the year, citing improved bilateral ties and ongoing technical and diplomatic discussions under the Trump administration.
As the year draws toward its close, Barrack has since emphasized that any progress remains conditional. In a December statement, he said United States law requires Turkey to no longer operate or possess the S-400 system as a prerequisite for restoring cooperation on the F-35, even as discussions continue in what he described as a more constructive atmosphere than in previous years.
The administration’s response to lawmakers reflects an effort to keep diplomatic channels open with Ankara while making clear that statutory requirements leave little room for flexibility on Turkey’s status in the F-35 program.
