European leaders quickly pledged their continued support for Ukraine on Friday after President Trump’s blistering criticism of Ukraine’s president, Volodymyr Zelensky, in a meeting at the White House.

Leaders lined up behind Ukraine and praised its embattled president, the statements coming one after the other: leaders from France, Germany, Poland, Spain, Denmark, the Netherlands, Portugal, the Czech Republic, Norway, Finland, Croatia, Estonia, Latvia, Slovenia, Belgium, Lithuania, Luxembourg and Ireland. Canadian, Australian and New Zealand leaders added their voices to the Europeans’.

Even as Western leaders generally shied away from explicitly criticizing Mr. Trump, who had told Mr. Zelensky he was “not in a good position” and angrily threatened to pull American support for Ukraine unless he agreed to a cease-fire deal with Russia, many in Europe addressed their statements of encouragement directly to Mr. Zelensky.

“Your dignity honors the bravery of the Ukrainian people,” Ursula von der Leyen, the president of the European Commission, said on social media, referring to Mr. Zelensky. “Be strong, be brave, be fearless. You are never alone, dear President.”

President Emmanuel Macron of France, who had put on a display of friendship with Mr. Trump during a chummy visit to the White House on Monday, said the United States and Europe had been justified in aiding Ukraine and imposing sanctions on Russia after its full-scale invasion of Ukraine three years ago.

In a statement, Mr. Macron urged America to remain on the side of the Ukrainians, who he said were “fighting for their dignity, their independence, their children, and the security of Europe.”

Friedrich Merz, who is on track to become Germany’s next chancellor after the country’s election this week, said in a statement addressed to “Dear Volodymyr” that his country would stand behind Ukraine “in good and in testing times.”

“We must never confuse aggressor and victim in this terrible war,” Mr. Merz added, apparently referring to Mr. Trump, who has called Mr. Zelensky a dictator and blamed him for the invasion. The departing German leader, Chancellor Olaf Scholz, said that Ukraine could rely on Germany and the rest of Europe.

Daniel Fried, a career diplomat under American presidents of both parties who had just returned from a trip to Brussels, said the Oval Office clash had jolted Europe’s capitals, generated a wave of sympathy for Mr. Zelensky and upended a peace process that appeared to be gaining traction.

“The Europeans are horrified and dismayed,” Mr. Fried said, adding that Europeans see the United States shifting to a great-power strategy in which large countries carve up the world. “They’re watching the America they know and respect change in a matter of a couple of weeks.”

Prime Minister Keir Starmer of Britain, a center-left leader who carefully avoided any major disagreements with Mr. Trump during a visit to the White House on Thursday, spoke with Mr. Trump and Mr. Zelensky on Friday, according to the prime minister’s office. Mr. Starmer “retains his unwavering support for Ukraine and is playing his part to find a path forward to a lasting peace,” the office said in a statement.

Mr. Starmer is scheduled to host in London an international meeting on Ukraine on Sunday with Mr. Zelensky and other leaders from across Europe.

Prime Minister Viktor Orban of Hungary, a right-wing nationalist who has long been at odds with much of Europe, appeared to side with Mr. Trump, saying on social media, “Strong men make peace, weak men make war.” He did not mention Ukraine or Mr. Zelensky in his post.

Mr. Trump’s upbraiding of Mr. Zelensky also predictably won praise in Russia. Dmitri Medvedev, a former Russian president who is deputy chairman of Russia’s Security Council, said on Telegram that Mr. Trump had told “the truth.”

The Canadian foreign minister, Mélanie Joly, joined the European leaders in offering words of support for Ukraine, telling reporters that Ukrainians were “fighting for their own freedoms, but also fighting for ours.”

Ms. Joly, whose country’s relationship with Mr. Trump has been deeply strained by the American president’s threats to annex Canada and plans to impose tariffs, stressed the importance of maintaining Western unity over the war in Ukraine. She said that the Russians were watching.

On Saturday morning in Australia, Prime Minister Anthony Albanese echoed the messages of support from Europe. Mr. Albanese said his country was proud to help Ukraine defend itself against “the brutality of Russian aggression.”

Mr. Zelensky responded to each European leader on social media, writing, “Thank you for your support.”

But he offered his most ample statement of gratitude to Mr. Trump, who had said in the Oval Office earlier on Friday that Mr. Zelensky was not “acting at all thankful” for American aid.

“Thank you America, thank you for your support, thank you for this visit,” wrote Mr. Zelensky, also thanking Mr. Trump, and adding, “Ukraine needs just and lasting peace, and we are working exactly for that.”

Stephen Castle, Christopher F. Schuetze, Nataliya Vasilyeva, Megan Specia and Qasim Nauman contributed reporting.