The two-man crew aboard the International Space Station is working to fix an air leak that is causing a drop in cabin pressure. The leak was first discovered late last month and is believed to have originated in a hose located on the U.S. side of the station.

American astronaut Michael Foale pinpointed the source of the leak and quickly set to work repairing it with the help of Russian cosmonaut Alexander Kaleri.

A spokesman with the U.S. space agency, NASA, said that the outcome of the effort is not likely to be known before Tuesday. But officials from both the U.S. and Russian space agencies say there is no immediate risk to the crew.

Space officials had earlier considered isolating the crew in the Russian side of the International Space Station, as cabin pressure dropped to a level close to that where equipment can fail.

Officials say the isolation plan no longer appears urgently necessary, but may still be carried out just to ensure the accuracy of the repairs.

If the crew fails to fix the leak, NASA says the next Russian Progress ferry spaceship will bring a new hose to the International Space Station later this month.

Russia's Progress cargo ships have been the sole suppliers to the space station since last February, when the breakup of the Space Shuttle Columbia on re-entry halted the U.S. program.