Alexander Rumyantsev said problems to date had been “purely technical”, but following proposed changes in contracts, Russian assistance in building Iran’s Bushehr power plant was likely to continue.
But the minister added that Moscow and Tehran still had points to discuss and would continue negotiations over Bushehr in Vienna later in the month.
The sticking point in the talks has been the return of spent nuclear fuel from the plant to Russia – with Moscow pressing Tehran to sign an agreement that would oblige it to return all of the fuel back to Russia.
"The signing of the agreement on the return of nuclear fuel... is a prerequisite for the start of deliveries of 'fresh' fuel," a source at the ministry told Russian news agencies on Saturday.
EU policy chief Javier Solana (c)
has also pressed Iran recently to
The minister’s comments come on the same day as the opening of a meeting of the International Atomic Energy Agency (IAEA) in Vienna, where the UN nuclear watchdog called on Iran to agree to tougher inspections of its nuclear facilities.
Iran must declare all its nuclear activities, the head of the International Atomic Energy Agency (IAEA) said on Monday.
"I'm going to strongly urge Iran to clarify all issues relevant to its enrichment programme to make sure that all its enrichment activities have been declared and are under agency verification," IAEA Director General Muhammad al-Baradai told reporters just before the meeting of the 35-nation board of governors.
The United States and Israel have been most vocal in complaining that the Bushehr project could help Iran develop a nuclear weapons programme.
Both countries have also urged Russia not to sign the agreement until Iran allows open inspections by UN teams of its military installations, despite Israel's continuing refusal to permit inspection of its own nuclear facilities.
Al-Baradai said Iran should also sign an optional additional protocol to the international Nuclear Non-Proliferation Treaty (NPT) which would give the UN's nuclear inspectors the power to make unannounced checks of its atomic facilities.
"[The protocol] gives us additional authority to make much more comprehensive and inclusive inspections," he said.
"Iran will in the near future sign the additional protocol"
Iranian foreign minister
Iran's foreign minister said on Saturday the Islamic Republic might soon agree to tougher nuclear inspections if ongoing talks on the issue with the IAEA removed "ambiguities".
"With explanations and the removal of ambiguities from the IAEA, Iran will in the near future sign the additional protocol," state news agency IRNA quoted Foreign Minister Kamal Kharazi as saying.
The United States reportedly asked the IAEA to sanction Iran for non-compliance with the nuclear non-proliferation treat, a step which would bring the issue to the UN Security Council.
But a diplomat in Vienna said Canada and Britain were "not going for a non-compliance resolution" since Iran had not cut off cooperation with the IAEA, as North Korea had done.
However, the US ambassdor to the IAEA, Ken Brill, said the UN's nuclear verification process in Iran had a "long way to go", adding that the IAEA board of governors needed "to take some action to help the agency".