Ankara’s possible purchase of US-made Patriot missile systems will not impact its deal with Russia to buy S-400 missile systems, Turkish presidential spokesman Ibrahim Kalin told a news conference on Monday, TASS reported.

"The deal on S-400 is closed. The first systems will be supplied in October 2019. The offer on Patriot will change nothing because we don’t consider them as alternatives to one another. We can have both systems," he said.

A source in the Turkish foreign ministry told TASS earlier that Turkey would use S-400 systems separately from NATO’s systems "and in a manner that will help preserve sensitive information concerning the F-35 aircraft."

It was reported on December 18 that the US administration had made a decision to sell Patriot surface-to-air missile systems worth $3.5 billion to Turkey. The permission was obtained for the sale of 80 Patriot MIM-104E surface-to-air missiles and 60 PAC-3 missiles and the corresponding equipment.