The US will stop its manufacturing support for F-35 fighter jets in Turkey if Ankara continues to pursue plans to acquire Russian long-range S-400 surface-to-air missile systems, acting Defence Secretary Patrick Shanahan told reporters on Friday.
“If Turkey decides that the S-400 is a decision they want to go forward with, then we have to move work out of Turkey”, he warned.
READ MORE: Turkey Hints It May Find Russian Substitute for F-35 Jets If US Halts Deliveries
Shanahan pledged to discuss options with representatives of US aerospace manufacturers Lockheed Martin and United Technologies should Turkey go ahead with plans to purchase S-400s.
The statement comes as House Armed Services Committee members, including Democratic Congressman John Garamendi, announced a bill to block the sale of the F-35 warplanes to Turkey if it goes ahead with its push to buy the Russian air defences.
“Operating the S-400 alongside the F-35 would compromise the aircraft and its sensitive technology, impact interoperability among NATO allies, and most importantly pose serious risk to our shared defence and security”, Garamendi said in a statement.
READ MORE: Turkish Pilots Continue F-35 Training Despite US Halting Deliveries – Report
He described the bill as a document which “sends a strong and important message to Turkey — proceeding with the S-400 is unacceptable and will not be tolerated”.
This comes amid ongoing tension between the US and Turkey over Ankara inking a loan agreement for the supply of S-400 systems with Russia in December 2017.
Washington is worried that the S-400’s radars will be able to learn how to spot F-35 stealth jets, which were originally scheduled for shipment to Turkey in 2019.
READ MORE: Turkish FM: S-400 Systems Acquired by Turkey Pose No Threat to F-35 Fighter Jets
Ankara, which has repeatedly signalled its commitment to the S-400 deal, insists that the S-400s are not a threat to the security of NATO, the US or the F-35 in any way. Despite this, Washington moved to stop deliveries of F-35 fighter jet parts to Turkey in early April.