The Pentagon said on Friday it had indefinitely postponed a press briefing on Turkey accepting delivery of an advanced Russian missile defense system.
The briefing was supposed to take place earlier on Friday with senior leaders on the Pentagon's response to the parts of the Russian made S-400 being delivered to Turkey.
The Pentagon added that Acting US Defense Secretary Mark Esper had spoken with his Turkish counterpart for about 30 minutes on Friday, but did not provide details on the discussions.
Turkish Defense Minister Hulusi Akar told Esper that his nation buying Russian missile systems does not mean a change of the country's strategic orientation.
Turkey's Defense Ministry also cited Akar as saying Ankara was still assessing the bid to acquire US Patriot air defense systems and that a deterioration of bilateral relations would not serve the interests of either country.