Billionaire Elon Musk's hand gesture at US President Donald Trump's inauguration drew online comparisons to a Nazi salute on Monday, but a leading anti-Semitism watchdog said it appeared to represent a moment of enthusiasm.

Musk dismissed criticism of the hand gesture as a “tired” attack.

Musk took the stage at Washington's Capital One Arena to a big cheer, waving his arms and yelling, “Yes!”

“This was no ordinary victory, this was a fork in the road for human civilization. This one was really important. Thank you for making it happen.”

Biting her lower lip, she thrust her right hand to her heart, fingers spread wide, then extended her right arm at a pointed, upward angle, palm down and fingers together. Then he turned and made the same hand motion to the crowd behind him.

“My heart goes out to you, it is because of you that the future of civilization is secured,” he said, ending the gesture.

Gestures were quickly verified online.

“Was Elon Musk Sig Hale at Trump's inauguration?” asked the Jerusalem Post.

The Anti-Defamation League, which monitors anti-Semitism, disagreed.

“Looks like @elonmusk made an awkward gesture in a moment of exuberance, not a Nazi salute, but again, we appreciate people being mad,” it posted on Monday.

“Very annoying”

In Germany, the president of the Jewish community of Munich and Upper Bavaria, Charlotte Knobloch, described the gesture as “deeply annoying”.

“Far more worrying are Elon Musk's political stances, his offensive interference in the German parliamentary election campaign and his support for a party whose anti-democratic aims should be under no illusions,” he said in a statement.

Musk has backed the far-right Alternative for Germany (AfD), an anti-immigration, anti-Islam party that German security services have labeled as far-right, in the upcoming national election.He broadcast with the party's leader on his social media platform earlier this month.

“Honestly, they need better dirty tricks. The 'everyone is Hitler' attack is so tired,” Musk said on his social media platform X late Monday.

Shortly after his speech, Musk posted a Fox video of excerpts from his speech at X, where he made his first gesture to face the cameras. “The future is so exciting,” he captioned it.

A spokesman for Trump did not immediately respond to requests for comment.

Some X users came to Musk's defense, claiming Musk was expressing “my heart goes out to you” and criticizing posts that suggested otherwise.