WARSAW, Poland (AP) — The new Polish Prime Minister Donald Tusk was sworn in by the president on Wednesday morning in a ceremony where each of his ministers was also taking the oath of office.

The swearing-in ceremony of the pro-European Union government was taking place in the presidential palace in Warsaw. It is the final step in a transition of power that has taken place this week.

It marks the end of eight tumultuous years of rule by a national conservative party, Law and Justice.

The government change follows a national election on Oct. 15 that was won by a group of parties that ran on separate tickets vowing to work together under Tusk's leadership to restore democratic norms eroded by Law and Justice and mend alliances with allies that were also strained.

Tusk and his ministers arrived at the presidential palace in a bus in the white and red colors of Poland’s flag and the words: “We thank you, Poland!” They were greeted by cheering supporters.

Tusk’s government won a vote of confidence in parliament on Tuesday evening after giving an inaugural speech there in which he vowed to demand that the West keep up its support for Ukraine.

Tusk called on Poland’s fractious political class to unite, saying it cannot afford divisions while Russia is waging a war of aggression across the border, a conflict many fear could spread if Moscow prevails.