Elon Musk's SpaceX is planning to fly private crew missions to the International Space Station in partnership with a California-based startup, the two companies said on Thursday.

The missions are contingent on approval by NASA and involve the firm Vast, which also aims to launch the world's first commercial space station as early as next year.

"Enabling payload and crewed missions to the ISS is a key part of Vast's strategy, allowing us to further our collaboration with NASA and global space agencies," Vast's CEO Max Haot said in a statement, which did not provide a timeline.