Turkey’s foreign ministry formally labeled the Russian-Ukraine conflict as a war, opening the way for the government in Ankara to restrict moves of Russian war vessels through the Bosphorus.

Turkish foreign minister Mevlut Cavusoglu said in an interview with CNN Turk on Sunday that the situation in Ukraine had turned into a full-blown war and that his country would therefore “transparently implement all the provisions” of the Montreux Convention — the international treaty that governs ship traffic through the Straits.