Donald Tusk the next European Council president

Prime Minister Donald Tusk has been chosen by EU leaders as the next European Council president, a move that cements Poland's emergence as an important player in the European Union ten years after it joined the bloc.

Herman Van Rompuy, the outgoing council president, announced Tusk as his successor at a summit in Brussels on Saturday. Tusk, a center-right pro-European, will start his a two-and-a-half-year term in the key EU post in December.

"I realize that the main task of the European Council president is constantly seeking compromise," Tusk, whose new job will see him chairing EU summits, told a press conference.

He added: "I realize that the main problems we face will not disappear in December. They include the crisis, which can still be felt, and the situation in the eurozone."

Donald Tusk, Federica Mogherini with Herman Van Rompuy

On the Ukraine crisis, Tusk said it was vital to "jointly work out a policy on the Ukraine-Russia conflict that is courageous but not radical and effective in achieving peace."

Analysts say that Tusk's appointment will give ex-communist countries in Central and Eastern Europe that are critical of the Kremlin new clout in the EU. Poland has been one of the most vocal supporters of sanctions against Russia over its involvement in the Ukraine crisis.