Russian President Dmitri Medvedev says his country is ready to consider new sanctions against Iran if persuasion fails to stop it from enriching uranium.
Mr. Medvedev says international efforts to influence Iran to suspend its sensitive nuclear work have been ineffective, but that Russia is hoping a deal can still be reached with Tehran.
He says new sanctions should be "smart" and should not hurt civilians.
Western nations have been pushing for a fourth set of U.N. Security Council sanctions against Iran for its nuclear program. Russia has long been reluctant to support tougher sanctions.
Iran says its nuclear program is for peaceful purposes. But on Monday, the new head of the International Atomic Energy Agency, Yukiya Amano, said it is impossible to verify whether that is true because Iran is not cooperating with his agency.
Iranian Foreign Minister Manouchehr Mottaki said Iran has fully cooperated with the IAEA and will continue doing so.
Amano criticized Iran in his first address to the group's board of governors in Vienna. The IAEA said for the first time last month that Iran may be trying to build a nuclear bomb.
Uranium enrichment is a process that can be used to make nuclear bombs.
Iran has refused to accept an IAEA-brokered deal to ship most of its enriched uranium to Russia and France for conversion into fuel for a medical research reactor. The plan was designed to curb Iran's ability to use the uranium for military purposes.
Iranian media reported Monday that Iran sent the IAEA a letter, explaining that Iran's government does not trust Western states with its nuclear fuel supply.
Some information for this report was provided by AFP, AP and Reuters.