Concern of regional destabilization mounts after Ankara launches ground offensive on Kurdish forces following US troop withdrawal from area

Iranian president's comments blaming Washington and Jerusalem for supporting Saudi Arabia in Yemen war made as he leaves for tripartite summit on Syria

Ankara's purchase of Russian-made missile defense system in defiance of US and NATO already cost it American F-35 stealth aircraft

Ankara's purchase of Russian S-400 air defense system 'renders its continued involvement impossible,' Pentagon says

Delivery moves Ankara closer to possible sanctions and new standoff with Washington, which has argued the weapon is incompatible with NATO systems and a threat to its F-35s

Statement comes after Washington threatened to remove Ankara from F-35 fighter jet program and have pilots kicked off training course and expelled from US over purchase from Russia

Acting defense secretary tells Ankara counterpart Washington will halt F-35 sale if S-400 deal goes ahead, but meeting ends without breakthrough

After Putin talks, Turkish president gives indication of timeframe for missile defense system's arrival, which may lead to Washington kicking Ankara out of F-35 fighter jet program

Washington says it may kick Ankara out of F-35 fighter jet program for deal with Russians; Turkish foreign minister: Country won't bow to 'ultimatums'

Officials warn training of pilots currently in America could also be halted over growing rift between Washington and Ankara