Ali-Asghar Soltanieh, the envoy to the International Atomic Energy Agency (IAEA), did not say if the joint venture enrichment was an alternative
"He… announced the basic agreement on a joint uranium enrichment firm on Russian soil and said that there are only some issues regarding technical, legal and financial matters that need more assessment or exchange of ideas," Radio quoted Soltanieh as saying from Russia.
Iran previously said in February that it had reached a "basic agreement" with Russia on jointly enriching uranium.
But little headway was subsequently made due to Tehran's refusal to suspend home-grown enrichment, the main demand of Western powers who are threatening to press for U.N. sanctions on Iran.
Western nations accuse Iran of seeking to develop nuclear weapons and insist that Iran halts uranium enrichment work which has military and civilian uses. Iran says it only wants to produce electricity.
Russia warns against pressure on Iran
Soltanieh was also quoted by the radio announcer as saying Iran would issue tenders next month for two nuclear power stations, in addition to one being built with Russian help near the southern port city of Bushehr.
It was not clear if he meant May or the next Iranian month, which starts on May 22.
Meanwhile, a top diplomat reiterated Moscow's opposition to sanctions or the use of force against Iran on Saturday, saying that turning up the pressure on Tehran will only aggravate the standoff over its nuclear program, Russian media reported.
"We firmly stand today for resolving the problems in and around Tehran diplomatically rather than militarily," the Interfax news agency quoted Oleg Ozerov, deputy director of the Foreign Ministry's Middle East and North Africa Department, as saying. "Increasing international pressure on Iran has no prospects."