"If for any reason the Progress M-51 does not make the delivery needed to assure the lives of the crew, Salizhan Sharipov and Leroy Chiao will have an emergency evacuation back to earth," ITAR-TASS said, quoting a statement from Russia's TsUP space mission control agency.

That delivery is scheduled for December 24.

TsUP said the two-man crew could be evacuated aboard the Soyuz capsule, a re-entry vehicle attached to the ISS for just such a purpose. For planning purposes only, a date had been set of December 30 for such an operation, should it prove necessary.

On Thursday, Russian space officials announced that the ISS crew was slowly running out of food and could have nothing left to eat within a matter of weeks.

The space station, which had been supplied by US space shuttles until the February 2003 Columbia disaster, is now only supplied by Russian craft, which have a much smaller cargo capacity.

"A lengthy pause in the flights of the space shuttles has complicated the situation with provision on board the ISS," Interfax quoted a spokesman with the Russian Space Agency as saying.

The official said that supplies would last until mid-January, making it crucial that a Russian cargo ship goes off without a hitch as scheduled on December 24.

"In this situation, any launch... is very important for the station and the crew," the official said.

All rights reserved. © 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.