LONDON — Volodymyr Zelenskyy met with British Prime Minister Keir Starmer on Saturday as European leaders grapple with the fallout from an extraordinary on-air exchange in which the Ukrainian president was loudly berated by Donald Trump.

Ahead of the meeting, Starmer told Zelenskyy, “We stand with you, with Ukraine, for as long as it may take. And I hope you’ve heard some of that cheering in the street that is the people of the United Kingdom coming out to demonstrate how much they support you, how much they support Ukraine and our absolute determination to stand with you.”

“I want to thank you, the people of the United Kingdom, such big support from the very beginning of this war,” Zelenskyy told Starmer.

“We’re really really happy that we have such partners and such friends,” the Ukrainian president added, saying that he’d also accepted an invitation to meet with King Charles on Sunday.

Zelenskyy was seen leaving 10 Downing Street with Starmer on Saturday evening after their meeting ended. Starmer went back inside, while Zelenskyy got into a car. Neither made a statement to the media.

European leaders are set to meet on Sunday at an emergency summit to discuss Russia and a peace plan for Ukraine.

Britain’s Starmer and President Emmanuel Macron of France have led efforts to convince Trump to continue supporting Ukraine, which was invaded by Russia three years ago. The spat in the Oval Office in front of the media has called into question whether that support will continue, and if the United States will proceed with a dramatic rapprochement with Russia’s Vladimir Putin.

Most European countries came out in support of Ukraine, breaking with Washington as differences in the trans-Atlantic alliance built over the past 80 years burst into public view.

“Today it became clear that the free world needs a new leader. It’s up to us, Europeans, to take this challenge,” European Union foreign minister Kaja Kallas said.

Friday’s meeting was meant to jump-start talks on a deal over Ukraine’s critical minerals, but degenerated into confrontation, with Trump and Vice President JD Vance criticizing Zelenskyy and telling him he wasn’t grateful enough.

European leaders quickly lined up to support the Ukrainian leader.

Zelenskyy’s “dignity honors the bravery of the Ukrainian people,” European Commission President Ursula von der Leyen posted on X. “Be strong, be brave, be fearless. You are never alone, dear President Zelenskyy. We will continue working with you for a just and lasting peace.”

“We must never confuse aggressor and victim in this terrible war,” wrote Friedrich Merz, the likely next leader of Germany.

Macron said it was essential to respect the Ukrainians “fighting for their dignity, their independence, for their children and for the security of Europe.”

Zelenskyy remained adamant that security guarantees be included in any agreement to end the war alongside the minerals deal drafted by the White House. These guarantees, he said, are the only thing that will keep Putin, who has a record of violating agreements, from continuing to fight in Ukraine and beyond.

On Friday, Trump told Zelenskyy he was being “disrespectful” and “gambling with World War III.”

“He disrespected the United States of America in its cherished Oval Office,” Trump said in a post on his Truth Social website after the meeting ended. “He can come back when he is ready for Peace.”

Trump later told reporters that Zelenskyy “overplayed his hand” and accused the Ukrainian president of “looking to go on and fight, fight, fight.”

After leaving the White House, Zelenskyy posted on X, “Thank you America, thank you for your support, thank you for this visit. Thank you @POTUS, Congress, and the American people. Ukraine needs just and lasting peace, and we are working exactly for that.”

During a Fox News interview Friday evening, Zelenskyy reiterated his appreciation of U.S. support but rebuffed calls to apologize for his comments at the White House.

Zelenskyy has repeatedly thanked the United States for its help. In December 2022, he spoke before both chambers of Congress and his first words were:

“Thank you so much. Thank you so much for that. Thank you. It’s too much for me. All this for our great people. Thank you so much. Dear Americans, in all states, cities and communities, all those who value freedom and justice, who cherish it as strongly as we Ukrainians in our cities, in each and every family, I hope my words of respect and gratitude resonate in each American heart.”

According to the Department of Defense, since February 2022, Congress has appropriated about $183 billion for Ukraine’s defense, though Trump has claimed that the U.S. has spent over $300 billion on aid to Ukraine.