Trusted Trump advisor and SpaceX founder Elon Musk on Friday expressed concern about President Donald Trump's proposed spending cuts to NASA, calling the news "troubling."

Musk has largely sided with the president on most issues, but the comment marks the second time this week that he has opposed Trump's policies. He openly expressed opposition to Trump's tariffs.

The billionaire made the NASA comment in a post on X, after news broke that the administration is reportedly looking to eliminate some of the science funding at the space agency.

"Troubling. I am very much in favor of science, but unfortunately cannot participate in NASA budget discussions, due to SpaceX being a major contractor to NASA," Musk wrote in response to a news article on the subject.

Reports indicate that the administration is looking to pull $5 billion from the agency's overall budget of $25 billion. But the bulk of the cuts are from the agency's Science Mission Directorate, which oversees all planetary science, Earth science, heliophysics, and astrophysics research.

The proposed budget includes funding for the agency's Hubble Space Telescope and the James Webb Space Telescope, but would eliminate funding for the Nancy Grace Roman Space Telescope, which is expected to launch in two years.

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.