The US' F-35 warplanes cannot operate in the same airspace as the Russian-made S-400 air defence system and Turkey knows this, US Secretary of State Mike Pompeo has told US lawmakers at a hearing Wednesday.
"It is not possible to both fly the F-35 in space where the S-400 is significantly operable," Pompeo said, speaking to members of the Senate Foreign Relations Committee. Washington has relayed this warning to Turkish authorities and defence officials, he added.
"The S-400 is a significant weapons system, and we've shared with them, we've asked them to go take a look at CAATSA, what that might well mean for them," Pompeo said.
The secretary emphasised that the US offer to sell Turkey the Patriot PAC air defence system was still on the table, and acknowledged Turkey's investment in the development of the F-35. "We've made clear to the Turks as plainly as we can, they build a significant component of the F-35. Not only are they purchasers and customers, but they are part of the supply chain for the F-35," he said.
Pompeo's remarks followed comments by Turkish Foreign Minister Mevlut Cavusoglu earlier Wednesday that Ankara may turn to Russia for advanced aircraft if it doesn't get its F-35s. "There are F-35s, but there are also aircraft manufactured in Russia. If we are not able to purchase the F-35, Turkey will buy similar aircraft from other countries," Cavusoglu said.
A day earlier, Cavusoglu warned that if the US and Turkey can't come to a mutually agreeable deal on the sale of the Patriot missile system, Ankara could simply buy more Russian S-400s.
Moscow and Ankara penned a $2.5 billion contract on the delivery of four battalion sets-worth of S-400s to Turkey in late 2017. Once deliveries start in July, Turkey will become just the fourth country in the world to possess the system after Russia itself, Belarus and China. Designed to stop enemy aircraft, drones, cruise and ballistic missiles, the S-400 is currently the most advanced mobile air defence system in Russia's arsenal.