A chartered spaceflight for India, Poland and Hungary's first astronauts in decades has been delayed indefinitely because of leak concerns at the International Space Station (ISS).

NASA said on Thursday that it wants to monitor the cabin pressure on the Russian side of the orbiting lab before accepting visitors. Officials stressed that the seven astronauts currently at the space station are safe and that other operations up there aren't affected.

SpaceX was supposed to launch four private astronauts this week on a 14-day space station mission, but bad weather and SpaceX rocket trouble delayed the flight. Then the station leak issue cropped up.

The Russian Space Agency has been dealing with cracks and air leaks in its station compartments for more than five years – "a top safety risk," according to NASA's Office of Inspector General. Recent repairs resulted in what NASA calls "a new pressure signature." Additional details were not immediately available.

The three Russians aboard the space station recently inspected the inside walls of the aging Zvezda service module, which launched in 2000, as well as a connecting tunnel. They sealed some areas and measured the current leak rate.

"Following this effort, the segment now is holding pressure," NASA said in an online update.

The private mission's delay provides extra time for NASA and the Russian Space Agency "to evaluate the situation" and determine whether more repairs are needed.

The chartered flight was arranged by the Houston company Axiom Space, and was to be Axiom's fourth trip to the space station with paying customers since 2022.

"This is the right thing to do," Axiom Space's executive chairman Kam Ghaffarian said in a written statement. "We will continue to work with all of our partners to finalize a new launch date."

The four astronauts – led by retired NASA astronaut Peggy Whitson, now an Axiom Space employee – will remain in quarantine in Florida.

NASA wants to keep the space station operating until 2030 before dropping it out of orbit. The goal is to replace it with a number of privately owned stations; Axiom Space is among the companies looking to fill the gap.