"It's going to be fantastic," he exulted on the day of Donald Trump's inauguration. Four months later, Elon Musk quietly brings his mission as advisor to the American president to an end.

Still, the president wants to mark the moment: “I’m giving a press conference tomorrow at 1:30 p.m. (5:30 p.m. GMT) with Elon Musk, in the Oval Office. It’ll be his last day, but not really, because he’ll always be with us, helping us until the end. Elon is amazing!” Donald Trump declared Thursday on his Truth Social network.