The leaders of the US and Russia have warned Iran that time is running out for talks over its nuclear programme, BBC reported.

President Barack Obama said Iran had failed "so far at least" to respond positively to a deal to send enriched uranium abroad for reprocessing.

Russia and France have offered to do this. Russia's Dmitry Medvedev said he was unhappy with the pace of talks, adding "other means" could be used.

The West suspects Iran wants to build weapons, but Tehran rejects this.

It says its programme is entirely peaceful.