"We are interested in continuing cooperation between Iran and the IAEA, so that everybody respects Iran's repeated statements that Iran does not have and will not have plans to develop a nuclear weapon," Lavrov said at a press conference in Moscow.

The decision by Iranian lawmakers, taken after a 12-day war that saw Israeli and US strikes on nuclear sites, still requires the approval of Iran's Guardian Council, a body empowered to vet legislation.

Lavrov said the decision was of "an advisory nature" to Iran's executive branch.

Moscow provides crucial backing for Tehran but did not swing forcefully behind its partner even as the United States launched strikes on Iran's nuclear facilities over the weekend.

Russia and Iran signed a milestone strategic agreement earlier this year, but it does provide for mutual assistance in the case of aggression.

Iran is Russia's second close ally to come under pressure in the Middle East in recent months, after Bashar al-Assad's regime in Syria was toppled last December.

It could be a sign that Russia's influence in the region is waning, as Moscow has to relocate resources and divert attention to its Ukraine offensive, according to Nikita Smagin, an independent expert on Russia-Iran relations.

Russia "is potentially losing its status as a superpower, at least as it perceived in the Middle East", he told AFP, adding that "its allies are being simply knocked out of the game, one after another".