Turkish Foreign Minister Mevlüt Çavuşoğlu and US Secretary of State Mike Pompeo had a telephone conversation, Report informs, referring to the State Department.
Pompeo said the purchase of S-400 anti-aircraft missile systems from Russia threatens US military personnel and military technology while allowing Russia access to the Turkish military and defense industry.
Pompeo confirmed on Twitter that he had spoken to Çavuşoğlu.
The US Treasury Department has imposed sanctions on four Turkish officials, including the head of the Turkish Defense Industry Administration, Ismail Demir.