A meeting between President Trump and Ukrainian President Volodymyr Zelenskyy in the Oval Office on Friday grew contentious, with Trump telling Zelenskyy that “you’re not acting at all thankful” for the support his country had received from the United States, saying the Ukrainian leader had been disrespectful, and telling him, “you’re gambling with World War III.”

Zelenskyy is in Washington to sign a deal that would give the United States access to Ukrainian rare earth and critical minerals. Trump said the leaders would sign it at an afternoon event at the White House.

It was unclear what would happen after the unusually undiplomatic session — with raised voices and cross-talk played out in front of television cameras. “Gonna be a tough deal to make, because the attitudes have to change,” Trump said.

The mood in the meeting changed when Vice President Vance accused the Ukrainian leader of being “disrespectful” for coming “to the Oval Office to try to litigate this in front of the American media.”

Zelenskyy asked, “Have you ever been to Ukraine? Have you seen the problems we have? Come once.”

The Ukrainian leader said, “Everybody has problems, even you. But you have nice ocean and don’t feel now. But you will feel it in the future.”

The argument came at the end of a lengthy question-and-answer session with reporters, after Trump defended his approach with Russian President Vladimir Putin, saying he was trying to broker a deal between two parties. “I’m not aligned with anybody. I’m aligned with the United States of America, and for the good of the world, I’m aligned with the world, and I want to get this thing over with,” Trump said.

Vice President Vance then defended Trump’s approach as “diplomacy.” That elicited a strong response from Zelenskyy, who described how Putin had broken previous deals. Vance accused Zelenskyy of trying to “litigate this in front of the American media,” accusing him of running propaganda tours and campaigning for Democrats in Pennsylvania during the election and being ungrateful.

“Offer some words of appreciation for the United States of America and the president who’s trying to save your country, please,” Vance said.

Asma Khalid contributed reporting from Washington, D.C.