President Donald Trump and Vice President JD Vance traded heated barbs with Ukrainian President Volodymyr Zelensky on Friday, calling the wartime leader “disrespectful” and saying he should be more “thankful” for continued U.S. support.

“You’re gambling with World War III,” Trump told Zelensky as the two sit next to each other in the Oval Office.

“Have you said ‘thank you’ once? You went to Pennsylvania to campaign for the opposition,” Vance chimed in.

The contentious back-and-forth between the world leaders comes after Trump called Zelensky a “dictator without elections” last week and suggested Ukraine was to blame for the start of its war with Russia in February 2022.

“You’re in no position to dictate what we’re going to feel,” Trump added during the meeting. “You don’t have the cards right now.”

During his visit to the White House, Zelensky is expected to seal a deal that gives the U.S. access to Ukraine’s rare earth minerals. In exchange, the U.S. will provide a security guarantee to Kyiv prevent future Russian aggression. After the intense exchange, it’s unclear how the minerals deal will be affected.