"I believe that the question is not so serious at the moment for the UN Security Council or the group of six to consider any introduction of sanctions," Ivanov said in Russia's far east.

In international practice, there have been no instances in which sanctions proved effective, he said, adding: "Russia stands for further political and diplomatic efforts to settle the issue."

To lure Tehran to suspend uranium enrichment, Britain, China, France, Russia, the United States and Germany put forward an international package in mid-June offering incentives and multilateral talks to Iran.

The package reportedly included talks with the United States, Western help to build nuclear reactors for Iran, a guaranteed supply of nuclear fuel and permission for Iran to buy aircraft and spare parts if Tehran suspends uranium enrichment.

Iran presented a 21-page formal response on Tuesday to the package, offering ideas that would allow serious talks to start immediately and asking for a timeline to implement the incentives and specifics on possible security arrangements. But there was no sign Iran has agreed to freeze its uranium enrichment.

The UN Security Council has warned Iran of possible sanctions if it does not meet an Aug. 31 deadline to freeze uranium enrichment, a process that can lead to the production of fuel for nuclear power plants or material for warheads.

The Security Council has not given its verdict on Iran's reply.

The United States accuses Iran of secretly developing nuclear weapons, but Iran insists its nuclear program is aimed at generating power to meet surging domestic demand.

Iran says it needs to enrich uranium as a peaceful, alternative energy source and has the right to do so under the nuclear Non-Proliferation Treaty.