The US has halted the delivery of support equipment and supplies to Turkey for F-35 jet fighter jets because of Ankara's decision to purchase the Russian-made S-400 missile system over repeated American objections.
"Pending an unequivocal Turkish decision to forgo delivery of the S-400, deliveries and activities associated with the stand-up of Turkey's F-35 operational capability have been suspended while our dialogue on this important matter continues with Turkey," Lt. Col. Mike Andrews told CNN in a statement on Monday.
"We very much regret the current situation facing our F-35 partnership, but the DoD (Department of Defence) is taking prudent steps to protect the shared investments made in our critical technology," he added.
The announcement comes as the Turkish Foreign Minister heads to Washington for a ministerial meeting marking the 70th anniversary of NATO.
"The US continues to warn Turkey of the negative consequences of its announced procurement of the S-400.
"We have, however, been clear that the acquisition of the S-400 is not compatible with the F-35 and Turkey's continued participation in the F-35 program is at risk," Andrews added.
Turkey has been involved with the F-35 development for a long time but senior US military and defence officials have long warned Ankara about the consequences of its pursuit of the Russian-made system, saying it was not compatible with NATO systems and posed an intelligence risk to the aircraft.
"While we continue the dialogue with our Turkish counter-parts, the DoD has initiated steps necessary to ensure prudent program planning and resiliency of the F-35 supply chain, as a result, secondary sources of supply for Turkish-produced parts are in development," Andrews told CNN.
Turkish pilots are currently training with the F-35 jets at Luke Air Force Base in Arizona.
Several Turkish companies have contributed to the development of the F-35 through work on the Lockheed Martin built airframe and the Pratt and Whitney propulsion system.
As a program partner, Turkish industries "are eligible to become suppliers to the global F-35 fleet for the life of the programme", according to information posted by Lockheed Martin, the jet's manufacturer.
The company says Turkey plans to purchase "100 of the F-35A Conventional Takeoff and Landing variant".
Twelve countries participate in the F-35 programme.
The nine partner nations that participated in the plane's development include the US, Turkey, UK, Italy, Netherlands, Canada, Australia, Denmark and Norway. All of these countries except for Canada, Denmark and Turkey are already receiving deliveries of the F-35. Israel, Japan and South Korea also have received the jets through foreign military sales.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)