Turkish leader gives no timeframe for arrival of missile defense system that is fraying ties with Washington

'It's not good,' US president says of S-400 deal during meeting with his Turkish counterpart at G20; Turkey refusing to backtrack despite American threats

Turkish citizen who translated for American drug enforcement agency accused of links to alleged mastermind of failed 2016 coup attempt

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

Turkish president declares purchase of Russian air defense missile system, which has angered Washington, is 'directly related to our sovereignty'

Turkish president says he has 'good' relations with US leader, is sure they can agree that sanctions over purchase of Russian air defense missiles is not 'suitable'

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

Ankara had previously signaled unwillingness to comply with American measures, but has now halted imports, government source says