Turkish Foreign Minister Mevlut Cavusoglu speaks during a news conference in Istanbul, Turkey October 30, 2018. REUTERS/Murad Sezer

ANKARA (Reuters) - Turkey may buy U.S. Patriot missile systems if conditions are right, but a deal will be impossible if Washington forces Ankara not to purchase the S-400 systems which it agreed to buy from Russia, Foreign Minister Mevlut Cavusoglu said on Thursday.

In an interview with broadcaster NTV, Cavusoglu said Turkey will not accept the United States imposing conditions regarding its deal to buy the Russian-made S-400 defense systems.