American actor and filmmaker Robert De Niro took potshots at former President Donald Trump in an MSNBC interview aired on Friday, and his comments did not go down well with Tesla CEO Elon Musk.

What Happened: In the interview, De Niro said “Trump is genuinely a sick person that somehow has been allowed into our system.” The actor opined that the former president can’t be anywhere near the office of the presidency.

De Niro, 80, said people don’t understand how dangerous Trump can be if he ever becomes president. “Historically, from what I have seen, even in Germany, they had it with Hitler.”

A potential second term for Trump could pose a risk to democracy, the actor said. “This guy is a monster and beyond wrong. It’s almost like he wants to do the most horrible things he can think of in order to get a rise out of us,” he said. “But he has been doing it and doing it and it is..scary.”

De Niro also thinks Trump will go after everybody and could even trigger civil strife. He also warned of things that happened in other parts of the world playing out in the U.S. “We always hear about people from eastern Europe, the Jews from other parts of Eastern Europe, from Western Europe coming over… Look what happened in France and with the Nazis and so on.”

“I’m just starting to see it. As a kid, Hitler was a nightmare [I thought] never would happen. But now I see that it is possible.”

When De Niro was asked about whether Biden was the right choice, he said, “I think he is the right guy. He is trying to do the right thing. We don’t have a choice.”

See Also: Ex-DOJ Attorney Says Former Trump Aide’s Testimony Sinks Ex-President’s Criminal Defense: ‘Big Fat Nail In The Coffin’

Musk Retorts: Reacting to a video clip of the interview shared on X, formerly Twitter, Musk said, “That dude [De Niro] is so out of touch it’s insane.”

In a separate post, Musk said the four years of Trump’s presidency and his policies bore no resemblance to those of Hitler. “So, this makes no sense,” he said. The billionaire also pointed to the peace accord Trump’s administration signed in the Middle East.

“In fact, with the Abraham Accords, he made some progress towards peace in the Middle East, which was definitely not high on Hitler’s agenda,” he said.

Musk is leaning toward the right, going by his comments on X, the social media platform he owns. The Biden administration and the Tesla CEO do not share a cordial relationship, with the former repeatedly snubbing the latter at the electric-vehicle summits organized by the White House. Biden, while applauding General Motors and Ford, has never openly acknowledged Tesla’s role in spearheading the EV revolution in the U.S.