Echoing what NASA officials said a day earlier, a Russian space official on Friday said the two-man crew on the international space station could be forced to return to Earth if a planned resupply flight cannot reach them with food supplies later this month.

"I don't want to discuss this possibility, and I won't call it emergency evacuation. I'd rather call it termination of the international mission ahead of time," said Russian Space Agency (search) spokesman Vyacheslav Davidenko.

A Progress supply ship carrying food and other supplies is slated for launch on Dec. 24 and would reach the station on Dec. 26. The crew has already been ordered to cut back on meals because food is running short.

Russian rockets and the non-reusable Soyuz (search) space craft have been the only way NASA can get to the space station and back since the U.S. shuttle fleet was grounded after the Columbia burned up on re-entry in February 2003, killing all seven astronauts aboard.

NASA's space station program manager, Bill Gerstenmaier, said on Thursday that there is enough food on the station to last seven to 14 days beyond Christmas Day.

Russian Mission control spokesman Valery Lyndin said that "there is no panic, the station is operating in its normal regime. The crew is working according to the program."

Davidenko said, "it is impossible to exclude, we don't have a 100 percent guarantee, but if the docking doesn't take place, we will implement the options that we are developing. We are not talking about an emergency, even if the docking doesn't take place Dec. 26, this would be a planned end to the flight, a planned landing."

If crew members Russian Salizhan Sharipov (search) and American Leroy Chiao (search) have to leave the station they would do so aboard a Russian-made Soyuz vehicle that is left docked to the station as a lifeboat.