BRUSSELS — European Union chief Donald Tusk says he will raise several thorny issues with Turkish President Recep Tayyip Erdogan at a meeting in Bulgaria next week, including Turkish military action in Syria.

Speaking after chairing a summit of EU leaders Friday, Tusk said they “strongly condemned Turkey’s continued illegal actions,” notably trying to stop gas exploration off Cyprus.

Tusk said “it will not be an easy meeting” on Monday in Varna, Bulgaria.

He said that he, European Commission President Jean-Claude Juncker and Bulgarian Prime Minister Boyko Borissov plan to raise “a number of complicated issues.”

Tusk said they would also discuss strained EU ties with Turkey — which is a candidate for membership in Europe’s rich club, although accession talks are at a virtual standstill — and the way forward.