Ukrainian President Volodymyr Zelenskyy said Sunday that if the U.S. takes Russian President Vladimir Putin’s side in Russia’s war on Ukraine, it will be a “historic mistake.”

On NBC’s “Meet the Press” on Sunday, host Kristen Welker asked Zelenskyy if he thinks Ukraine can win the war without the United States.

Zelenskyy admitted that it would be “very difficult.”

“But if [the] United States will support Putin, I mean, it’s unbelievable. It’s a tragedy,” he said. “It’s a historic mistake and a big tragedy. I don’t want to live in illusions, but I think that we have to be pragmatic. If the United States will officially take the side of Russia, of course, if these two countries will be together, of course, we will not prevail and we will not be able to stand.”

Zelenskyy added that Ukraine hopes the Trump administration will be on its side or, at minimum, “in the middle.”

Ukrainian President Volodymyr Zelenskyy and President Donald Trump.

Getty Images/YouTube.

Trump has accused Zelenskyy of being harder to deal with than Putin, a comparison the Ukrainian leader dismissed.

“We can’t compare with Russia,” Zelenskyy said. “We can’t compare me and Putin. He’s aggressor. He occupied us. He killed adults and children, his soldiers. He’s a terrorist. And that’s why I hope that President Trump will be very clear with this position.”

“I can’t applaud any decisions or any words of one or another leader if they go against Ukraine, if they are supportive for Russia, and directly for Putin. He’s a killer. That’s why I’m very honest and open to say that he’s a killer,” he added.

Watch Zelenskyy’s interview below: