WASHINGTON, United States (AFP)— Billionaire tech mogul Elon Musk said Tuesday his critics needed “better dirty tricks” after a row erupted over a gesture he made at an inauguration event for US President Donald Trump that some likened to a Nazi salute.

The X, SpaceX and Tesla chief appeared on stage at the Capital One Arena in Washington, where supporters of the newly inaugurated president had gathered for a rally.

Upon thanking the crowd for returning Trump to the White House, Musk tapped the left side of his chest with his right hand and then extended his arm with his palm open, repeating the gesture for the crowd seated behind him.

Claire Aubin, a historian who specialises in Nazism within the United States, said Musk’s gesture was a “sieg heil,” or Nazi salute.

“My professional opinion is that you’re all right, you should believe your eyes,” Aubin posted on X, aligning with those who found the gesture was an overt reference to Nazis.

But Musk later posted on X that his opponents needed “better dirty tricks.”

“The ‘everyone is Hitler’ attack is sooo tired,” he said.

Musk has also made several statements in recent weeks in support of Germany’s far-right AfD party and British anti-immigration party Reform UK.

But the Anti-Defamation League, an organisation founded to combat anti-Semitism which has criticised Musk in the past, defended his actions this time around.

“It seems that Elon Musk made an awkward gesture in a moment of enthusiasm, not a Nazi salute,” the organisation said in a statement posted on X.

Another historian, Aaron Astor, also rebuffed accusations of Musk’s Nazi emulation.

“I have criticised Elon Musk many times for letting neo-Nazis pollute this platform,” he wrote on X, adding: “But this gesture is not a Nazi salute.”

“This is a socially awkward autistic man’s wave to the crowd where he says ‘my heart goes out to you.'”

Musk announced in 2021 he had been diagnosed with Asperger’s syndrome, a form of autism.

One attendee at the rally told AFP he thought Musk was making the gesture as a joke.

“He’s very humorous, and he uses a lot of sarcasm. So when he did that on the stage, I don’t think he meant it,” said Brandon Galambos, a 29-year-old pastor and tech worker.

Still, reports by Wired and Rolling Stone magazines said far-right personalities in the United States were celebrating the move, such as the writer Evan Kilgore, who called the salute “incredible.”

Ruth Ben-Ghiat, a historian of fascism, found the gesture “was a Nazi salute — and a very belligerent one too,” she said on X.

Democratic Party members also quickly responded with alarm.

Congressman Jimmy Gomez reacted to the moment by posting on X: “Well, that didn’t take long.”