A group of US senators in a letter on Tuesday urged Defense Secretary Mark Esper to remove Turkey from the F-35 fighter jet supply chain
"Unfortunately, Turkish manufacturers are still producing and delivering key components of the [F-35] aircraft despite the statutory prohibition on such participation in manufacturing line of the program. We believe more urgency is needed and hope you will accelerate the process to ensure a more prompt removal," the senators said.
In the letter, Republicans James Lankford and Thom Tillis and Democrats Jeanne Shaheen and Chris Van Hollen cite alleged Turkish transgressions, including defense cooperation with Russia, detention of Americans and human rights violations to justify the removal.
Since 2018, the United States has introduced a number of bills designed to pressure the Turkish government into canceling the purchase, including removing Turkey from the F-35 fighter jet supply chain, despite the added costs to the program and US taxpayers.
The US has proposed buying the S-400s from Ankara in a bid to break the deadlock over the weapons, which Washington says are incompatible with NATO security standards and might compromise the operations of the new fifth-generation F-35 fighter jets. Ankara has repeatedly vowed to activate the missile systems, delivered by Russia last summer, despite US sanctions threats.
Last month, Russia and Turkey agreed in principle on the second shipment of the S-400 air defense systems, according to the head of the Turkish defense industry secretariat, Ismail Demir. The first shipment was delivered to Turkey in 2019.