Trump said last December, before returning to office, that he wanted the online payments entrepreneur and the first private astronaut to conduct a spacewalk to serve as the next head of NASA.

But the New York Times reported Saturday that Trump will withdraw that nomination, quoting unnamed sources as saying the decision had come after the president learned Isaacman had donated to prominent Democrats.

Asked about the report, the White House confirmed the nomination shift.

"It's essential that the next leader of NASA is in complete alignment with President Trump's America First agenda," it said in an email to AFP.

"A replacement will be announced directly by President Trump soon."

The move appears to be a snub of billionaire Elon Musk, who on Friday stepped back from his role leading Trump's so-called Department of Government Efficiency (DOGE).

Musk reportedly lobbied directly with the president for Isaacman, who has had significant business dealings with Musk's SpaceX, to get the top NASA job, raising questions of possible conflicts of interest.

As the news surfaced, Musk stressed on X that "it is rare to find someone so competent and good-hearted".

The 42-year-old founder and CEO of Shift4 Payments has emerged as a leading figure in commercial spaceflight through his high-profile collaborations with SpaceX.

He made history last September by stepping out of a Crew Dragon to gaze at Earth from the void of space while gripping the spacecraft's exterior, during the first-ever spacewalk carried out by non-professional astronauts.