Iran on Sunday said it would be willing to discuss Moscow's proposal to move uranium enrichment to Russia if the U.N. Security Council were to send its case back to the International Atomic Energy Agency (IAEA).
"The Russian proposal is still on the table," Iranian Foreign Ministry spokesman Hamid Reza Asefi told a news conference.
"Within this framework it is normal that we will review different proposals on when it is carried out and under what conditions," he added.
Iran, which says its nuclear programme is for energy not weapons, could face a new resolution at the U.N. Security Council after the IAEA reported on Friday Iran has hampered its checks and rebuffed requests to stop making nuclear fuel.
U.N. ambassadors from the United States, Britain and France were expected to begin drafting a resolution on Monday they hope to introduce within a week which would obligate Iran to comply with the council's demands.
With the clock ticking towards possible Security Council action, Tehran has remained defiant and said it would continue to enrich uranium and develop its atomic energy programme.
But in the past two days Iran has suggested steps to ease the crisis.
On Saturday Iran offered to allow spot checks by IAEA inspectors if the Security Council dropped the case. On Sunday, Iran said it would consider Moscow's plan under which uranium for use in Iranian power stations would be enriched in Russia.
"Research enrichment has started and it is going on and it is irreversible," Reza said.
"We want to see to it that industrial enrichment and industrial production should come from the heart of negotiations," he added.