Elon Musk may be winding down his time in Washington D.C. but he's staying close to Donald Trump's side, including joining the president on his Middle East trip.

Musk and several of the biggest names in American businesses attended a Saudi-U.S. investment forum in Riyadh on Tuesday, joining Trump and the Saudi crown prince for a lavish luncheon.

The Tesla founder traveled to Saudi Arabia independently of Air Force One. He is, however, listed as one of the speaker's at Trump's forum. Trump introduced Musk to Saudi Crown Prince Mohammed bin Salman Al Saud.

A crowd of the who's who on Wall Street and in Silicon Valley also is there, including OpenAI CEO Sam Altma, Musk's brother Kimbal, FIFA President Gianni Infantino, LinkedIn's Reid Hoffman, Amazon's Andy Jassy, Google's Ruth Porat, and Boeing's Kelly Ortberg.

The president introduced them one-by-one as part of a formal greeting with the crown prince.