At one point, when Zelenskyy tried to respond, an angry Trump accused him of “gambling with World War III.”

A Europe already rattled by Trump’s overtures to Russia’s President Vladimir Putin quickly rallied around Zelenskyy, with the European Union’s top diplomat, Kaja Kallas, saying in a statement that it’s “clear that the free world needs a new leader”.

“It’s crucial for us to have President Trump’s support,” Zelenskyy said in a series of posts on X on Saturday morning.

“He wants to end the war, but no one wants peace more than we do.”

Zelenskyy emphasised his gratitude for the US’ backing of Ukraine in the three years since Russia invaded his country.

In Friday’s fiery exchange, Vance questioned whether the Ukrainian leader had been thankful enough for US support.

“We are very grateful to the United States for all the support. I’m thankful to President Trump, Congress for their bipartisan support, and American people. Ukrainians have always appreciated this support, especially during these three years of full-scale invasion,” Zelenskyy reiterated in his posts on social media.

The Ukrainian leader stressed that, despite Friday’s clash, Ukraine and the US “remain strategic partners. But we need to be honest and direct with each other to truly understand our shared goals.”

He said that Ukraine is ready to sign the minerals agreement that he had travelled to the US to hammer out, but noted that “it’s not enough,” highlighting the absence of the security guarantees he’s been seeking.

“We need more than just that. A ceasefire without security guarantees is dangerous for Ukraine. We’ve been fighting for three years, and Ukrainian people need to know that America is on our side,” Zelenskyy said.

Starmer told Zelenskyy on Saturday that Ukraine has the UK’s “full backing” as they met at the British leader’s official residence in London.

Starmer expressed “his unwavering support for Ukraine,” according to an official readout of the meeting from Downing Street.

The two leaders signed an agreement to accelerate US$2.8 billion ($4.5bn) worth of loans to Ukraine – to be paid off by frozen sovereign Russian assets.

Zelenskyy said the funds would go toward the production of weapons in Ukraine, and added that he and Starmer spoke about “reliable security guarantees”.

Zelenskyy also announced that King Charles had accepted an invitation to meet on Sunday.

Zelenskyy’s UK trip comes ahead of a summit of European leaders on Sunday, which was announced amid growing concern that the Trump administration’s push to work with Russia could exclude Ukraine from deciding its own fate.

Just last week, Trump wrongly accused Ukraine of starting the war with Russia and called Zelenskyy a “dictator”.

The week before, he said that Ukraine “may be Russian someday” when discussing what has now become the minerals agreement.

Russian officials reacted with glee to Friday’s fractious meeting. Dmitry Medvedev, the former Russian president, said Zelenskyy had “finally got a proper slap down in the Oval Office”.

Meanwhile, a flurry of Western countries took to X to show their staunch support for Kyiv.

A joint statement by the leaders of the European Union, said that Zelenskyy’s “dignity honours the bravery of the Ukrainian people.”

NATO chief Mark Rutte called the fractious Zelensky-Trump meeting “very unfortunate.” In an interview with BBC News, Rutte added that “it is important that President Zelenskyy finds a way to restore his relationship with the American president and with the senior American leadership team.”