Ankara likely to face sanctions unless it gives up air defense system, US says could endanger F-35 fighters and give sensitive information to Russians

US president will challenge Erdogan on S-400 when he visits White House this week, national security adviser says

Turkish leader states intention to follow up on matter with his American counterpart at the UNGA; says EU must give more support for Syrian refugees or 'we will open the gates'

Washington says Ankara's obtainment of anti-aircraft missile system may endanger American warplanes

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

Officials from Jerusalem said to have pressured Washington behind the scenes to exclude Ankara from fighter jet program in bid to preserve military qualitative edge

Turkish president vows to 'take measures' after US bans sale of F-35 to his country over its purchase of Russian system

Washington excludes NATO ally after it buys Russian missile defense system after repeated warnings

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

Turkish leader defiant amid US sanctions threat over Russian missile deal, says 'taking every measure' to prevent repeat of attempted putsch that led to mass crackdown