WARSAW, Jan. 3 (Xinhua) -- A gala was held on Friday at the National Opera in Warsaw to mark Poland's inauguration as the presidency of the Council of the European Union (EU).

Speaking at the event, Polish Prime Minister Donald Tusk said he will address the European Parliament on Jan. 21 to outline "the ambitious intentions of the European Union, the whole of Europe and the Polish presidency for these very difficult six months."

European Council President Antonio Costa emphasized that the Ukraine issue remains a priority for the EU. He thanked Tusk for his efforts in preparing for an informal meeting of EU leaders scheduled for February.

"There is no better time for Polish leadership in the European Union," Costa said.

Poland's presidency began on Jan. 1 and will continue until the end of June. This marks the second time Poland has held the EU's six-month rotating presidency, the first being 2011. ■