Ursula von der Leyen sent her congratulations via social media on Monday night, Polish state news agency PAP reported.
The top EU executive wrote on the X platform: "Congratulations Donald Tusk on becoming Poland’s Prime Minister. Your experience and strong commitment to our European values will be precious in forging a stronger Europe, for the benefit of the Polish people."
She added: "I look forward to working with you, starting with this week’s important European Council."
Earlier on Monday Tusk, a former top European Union official, was elected Poland's new prime minister, returning to the role he held between 2007 and 2014.
MPs chose Tusk as the country's new head of government in a 248-201 vote, ending eight years of rule by the right-wing Law and Justice (PiS) party.
In a speech to parliament afterwards, Tusk thanked "millions of Poles" for backing pro-EU opposition parties in the October election, thus removing Law and Justice from office and helping effect a "historic change" in the country.
He said he "had to return" to the prime minister's role and thanked his family for patience, the PAP news agency reported.
European Parliament chief sends congratulations
Meanwhile, European Parliament President Roberta Metsola also congratulated Tusk on his becoming Poland's new prime minister.
Metsola wrote on X that she looked forward to "working together for a prosperous Poland and a stronger Europe," the PAP news agency reported.
She described Tusk as a "staunch believer in the European Union and a dear friend." She added: "We will tackle current challenges. United."
President accepts resignation of PM Morawiecki
President Andrzej Duda accepted the resignation of conservative Prime Minister Mateusz Morawiecki, whose new Cabinet lost a vote of confidence in parliament earlier on Monday.
It paved the way for a coalition of pro-European opposition parties led by Tusk to take power, the PAP news agency reported.
Duda also met with Tusk on Monday night and declared he would swear in his Cabinet at 9 a.m. on Wednesday, according to officials.
Tusk is expected to give a speech to lawmakers on Tuesday laying out his government's plans, followed by a parliamentary vote of confidence.
Tusk's return as prime minister sets the stage for a thawing of Poland's relations with the European Union, the Reuters news agency reported.
The new head of government has vowed to unblock billions of euros in grants and loans from the EU, frozen due to Warsaw's dispute with Brussels over democratic standards.
Tusk last Friday unveiled the lineup of his future Cabinet and urged the head of state to appoint his government on December 13, in time for a crucial EU summit starting in Brussels the next day.
He said the summit would make decisions "of great importance to Poland's interests."
EU leaders are expected to discuss the war in Ukraine and a protest by Polish haulers at the border with Ukraine, among other topics, according to officials.
Tusk was Poland's prime minister from 2007 to 2014 before becoming president of the European Council, a role he held until 2019.
(pm/gs)
Source: PAP, rp.pl
