WASHINGTON (Reuters) - 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 U.S. Defense Secretary Mark Esper had spoken with his Turkish counterpart for about 30 minutes on Friday, but did not provide details on the discussions.