Turkey accepted the first shipment of a Russian surface-to-air S-400 defence system at a military airport in Ankara on Friday, thereby defying warnings and threats of sanctions from the US.

“The first phase of the S-400 delivery has started with a plane that has landed in Ankara,” the Turkish Defence Industry Directorate, which reports to President Recep Erdogan, said on its website.

The directorate added that the delivery would continue in the coming days. It was not immediately clear when the system would be installed and activated for use.

The purchase has become a bone of contention between NATO allies, Ankara and Washington, with The White House strongly opposed to the system’s use in NATO airspace citing practical and security concerns.

Washington has threatened to impose sanctions and remove Turkey from the F-35 joint strike fighter programme if Ankara accepts delivery of the air defence system.

Washington fears that Russia could spy on the advanced US F-35 stealth fighter jet through the S-400 radars. Turkey is a partner in F-35 production and expects to buy more than 100 jets.

Earlier in the day, Turkey’s Defence Ministry said “the first group of equipment of the S-400 long-range regional air and missile defence system has started to Murted Airport,” referring to a military airport in the Turkish capital.

Erdogan confirmed on Monday that preparations for the shipment of the weapons system were underway, and said on Wednesday that Turkey would use the system “wherever and however we need them.”