A bipartisan initiative is underway in the U.S. Congress to prevent Turkey from rejoining the F-35 fighter jet program. The effort is being led by Democratic Representative Dina Titus of Nevada following comments by President Donald Trump suggesting that a new defense arrangement with Ankara could be possible ahead of the upcoming NATO Summit in Turkey.

According to a draft letter currently circulating for signatures, lawmakers will urge House leadership to be prepared to use Congress’s legal authority to block any decision allowing Turkey back into the F-35 program unless the issues surrounding its Russian-made S-400 air defense system and the CAATSA sanctions have first been resolved.

Under the Arms Export Control Act, Congress has the authority to attempt to stop major weapons sales through a joint resolution of disapproval. This formal legislative mechanism becomes available after the administration officially notifies Congress of a proposed arms sale.

The letter will be sent to House Majority Leader Steve Scalise and House Democratic Leader Hakeem Jeffries. It argues that the Trump administration cannot bypass existing U.S. legal obligations while Turkey continues to possess the Russian S-400 missile defense system.

Triggered by Trump’s remarks

The congressional initiative follows comments President Trump made during a White House meeting with NATO Secretary General Mark Rutte. Asked whether he planned to travel to Turkey with a “big bag of gifts”—a reference to Ankara’s requests for General Electric aircraft engines and F-35 fighter jets—Trump replied affirmatively.

The letter notes that these remarks came ahead of the NATO Summit scheduled to take place in Ankara on July 7-8.

Its authors also cite Vice President J.D. Vance, who recently stated that an official review is already underway examining how a potential sale could legally proceed. According to the letter, Vance said that “Pete Hegseth and the entire team are looking at the issue right now.”

Turkey’s removal from the F-35 program

Turkey was expelled from the F-35 program in 2019 after purchasing the Russian-made S-400 air defense system. Washington concluded that operating the S-400 alongside the fifth-generation fighter posed an unacceptable risk to sensitive information regarding the aircraft’s capabilities.

The letter also recalls that in December 2020, during President Trump’s first administration, the U.S. State Department imposed sanctions on Turkey’s Presidency of Defense Industries under Section 231 of the Countering America’s Adversaries Through Sanctions Act (CAATSA). Those sanctions, lawmakers emphasize, remain fully in force.

Lawmakers argue legal barriers remain

The central legal argument is that Turkey’s acquisition of the S-400 constituted a significant transaction with an entity connected to Russia’s defense and intelligence sectors.

The lawmakers argue there is no publicly available evidence showing that Turkey has:

• Removed the S-400 system;
• Taken it out of operational service; or
• Addressed the underlying issues that led to the sanctions.

Beyond CAATSA, the letter also cites the Fiscal Year 2020 National Defense Authorization Act, which prohibits transferring F-35 aircraft to Turkey unless Ankara no longer possesses the S-400 system, guarantees it will not seek to acquire it again, and confirms it has not accepted additional S-400-related deliveries or similar systems that could compromise U.S. defense technology.

The lawmakers further reference testimony before the House Foreign Affairs Committee on June 3, 2026, during which Secretary of State Marco Rubio reportedly acknowledged that the administration remains legally obligated to maintain sanctions on Turkey and cannot simply readmit Ankara to the F-35 program.

Early congressional action

Through this initiative, Rep. Titus hopes to mobilize Congress before the administration formally moves toward reopening the F-35 program to Turkey.

The letter argues that any such decision should not be viewed solely as a matter of defense policy but also as one of compliance with binding U.S. law.

How Congress can block an arms sale

When the White House approves a major arms sale, Congress has the option of introducing a joint resolution of disapproval under the Arms Export Control Act.

However, successfully blocking a sale is difficult in practice.

Once the administration formally notifies Congress, lawmakers typically have 30 days—or 15 days for NATO allies and certain close U.S. partners—to introduce such a resolution.

For the resolution to halt the sale, it must pass both the House of Representatives and the Senate in identical form. It must then either be signed by the president or survive a presidential veto.

As a result, while a simple majority may be sufficient to send a strong political message, it is generally not enough to stop an administration determined to proceed. Overriding a presidential veto would require a two-thirds majority in both chambers of Congress.