Turkish Prime Minister Binali Yıldırım has talked on the phone with German Chancellor Angela Merkel over Germany’s decision to ban Turkish ministers from holding events in two German cities ahead of the April 16 constitutional referendum that will decide whether the current parliamentary system should be shifted to an executive presidency.

“We talked about the restrictions on the phone. It was a good and productive conversation,” Yıldırım said on March 4, as he added that Turkish Foreign Minister Mevlüt Çavuşoğlu and his German counterpart Sigmar Gabriel will meet next week.