WASHINGTON -- The White House said on Saturday that US President Donald Trump will soon announce a new nominee for the head of NASA, following his decision to withdraw former candidate Jared Isaacman, a close ally of Elon Musk.

"After a thorough review of prior associations, I am hereby withdrawing the nomination of Jared Isaacman to head NASA," Trump wrote on his Truth Social site. "I will soon announce a new Nominee who will be Mission aligned, and put America First in Space."

Late last year, Trump named Isaacman, a billionaire and private astronaut, as the nominee for NASA chief. The Senate Commerce, Science and Transportation Committee approved his nomination in late April.

Isaacman, a close associate of Musk and a major client of his company SpaceX, has purchased several private spaceflights from the company with hundreds of millions of dollars.