President Putin spoke via a link-up to the station's crew

Russia has indicated that it may expand its role at the International Space Station (ISS), following the loss of the US space shuttle Columbia earlier this year.

Russian President Vladimir Putin said he recognised the responsibility which Russia had to carry in light of the US space agency's (Nasa) decision to suspend all shuttle flights.

Mr Putin was speaking via a video link to the ISS's current three-man crew on Cosmonauts Day, which marks the first manned flight into space on 12 April 1961.

He told the crew that they had dealt brilliantly with the difficult task of continuing operations at the space station in the weeks following the loss of Columbia and the seven astronauts on board.

"Today, as shuttle flights are temporarily grounded, it is important to keep the ISS in working order," Itar-Tass news agency quoted Mr Putin as saying.

"The Russian Government has already taken the decision to concentrate necessary resources to build additional craft to be sent into orbit. If it comes to it, we will look at the question of Russia taking on further work in the ISS."

Replacement crew

Cosmonauts Day remains a source of great pride in Russia

Since the Columbia disaster in February, Nasa has put a freeze on shuttle flights, leaving the ISS dependant on Russian craft to carry food, fuel and crews into space.

Despite the Russian Government earmarking an extra 1.2bn roubles ($38m dollars) to the space programme earlier this month, analysts say it is unlikely Russia can produce any more rockets than those already in the production line.

The ISS is currently manned by US station commander Ken Bowersox, science officer Donald Pettit and Russian cosmonaut Nikolai Budarin.

They were due to return to earth aboard the Atlantis shuttle last month, but will now be ferried down aboard a Russian Soyuz craft in early May.

Their replacement crew - Russian Yuri Malenchenko and US astronaut Edward Lu - is due to blast off from Russia's Baikonur cosmodrome on 26 April.