The Turkish newspaper Hurriyet Daily News cited Ibrahim Kalin, the Turkish President's spokesman as saying that "work for delivery of Russian S-400 missile defense systems within 2019 has been finalized," which is not the case with the US Patriot interceptors.
Singling out "objective criteria" on purchasing foreign air defenses, Kalin specifically stressed Ankara's priority pertaining to the joint production of such systems.
"We could not agree with the production company of the Patriots [during previous talks],"while the Russian side has "taken quicker steps," he underscored.
Kalin made it plain that Ankara would go ahead with talks on the purchase of the Patriot systems if Washington "meets the required conditions." According to him, "the ball is in the US' court."
Kalin also said that Turkey's NATO membership will not affect Ankara acquiring the S-400 systems, which he recalled are being purchased for defense purposes. According to him, it will not pose a threat to the alliance.
Speaking at a press conference after his talks with Turkish counterpart Recep Tayyip Erdogan earlier this week, Russian President Vladimir Putin said that Moscow and Ankara have agreed to speed up the delivery of the S-400 systems to Turkey.
In December 2017, Russia and Turkey signed a loan agreement on the purchase of the Russian-made S-400 surface-to-air missile systems.
The deal stipulates that Russia will supply Turkey with four batteries of the S-400s, to be maintained by Turkish personnel. The initial delivery of the batteries to Ankara is planned for the first quarter of 2020.
The parties also agreed on technological cooperation in order to develop the production of similar missile systems in Turkey.
Late in February, the Turkish newspaper Haberturk cited an unnamed US official as saying that Washington is concerned about Ankara's push to buy Russian S-400 systems.
The official warned that it may "negatively influence the interoperability of NATO" and that the White House may introduce punitive measures in response.
"We want to help Turkey find a better alternative to meet its air defense needs," the official said.
Earlier, it was reported that Washington is doing its best to prompt Ankara to buy the Patriot systems instead of the S-400s.