The fact that other countries are demanding Turkey ditch the S-400 air-defence systems it purchased from Russia is unacceptable, Turkish Foreign Minister Mevlut Cavusolgu told reporters during a visit to Athens. This reported by Sputnik.

"We will have full control of the S-400 systems. Our technicians went to Russia to undergo training but there will be no Russian military experts in Turkey. So, other countries' demands not to use S-400 are unacceptable," the minister said, as quoted by TRT channel. 

Ankara signed a deal with Moscow to purchase its S-400 air-defence systems in 2017 and the first deliveries began in July 2019. The deal sparked a row between Ankara and Washington because Turkey also participated in the US F-35 programme and was waiting for delivery of its fighter jets. The US says Turkey won't be sent the aircraft unless it backtracks on the S-400 deal with Russia – Washington says that the Russian systems are incompatible with shared NATO defences and threaten its F-35s, while Ankara insists that the S-400s will operate independently from NATO defences.