Russia pitched on Wednesday a proposal to Iran's foreign minister which it hopes could bring a breakthrough in a confrontation over Tehran's nuclear programme, despite doubts in the West that the plan can make much headway.

Since talks between global powers and Iran foundered in January, Russia has advocated a phased plan in which Tehran would address concerns that it may be seeking nuclear weapons, and be rewarded with an easing of sanctions.

Russian Foreign Minister Sergei Lavrov said after meeting his Iranian counterpart Ali Akbar Salehi that he hoped the plan would lead to new talks between Iran and the powers -- Russia, the United States, Britain, France, China and Germany.

"We hope this will help us move forward faster than has been the case until now and that we can resume negotiations soon," Lavrov told a joint press conference with Salehi.

Salehi said the proposal had good elements and that Tehran's reaction was "positive," but suggested that a final resolution to the long-running dispute could still be far off. "We agreed that we will study all the details of this project and will continue to perfect it through expert work," he said.

"A very long journey begins with a first step," Salehi said, adding that Iran was ready for talks but would not be pressured.

Iranian President Mahmoud Ahmadinejad also welcomed the Russian proposal in Tehran on Tuesday.

Previous initiatives from Russia and others have collapsed after initial expressions of interest from Iran, and neither Moscow nor Tehran has made details of the proposal public.

Iran has given no indication that it is ready to address the Western powers' main concern, its uranium enrichment activities, which they fear are aimed to develop weapons.

"To be realistic one has to recognise that there is this fundamental difference between the two sides, and what has been described as Moscow's proposal doesn't seem to address the basic problem of Iran's continuing enrichment," London-based proliferation expert Mark Fitzpatrick, a director at the International Institute for Strategic Studies, told Reuters.

Shannon Kile, a nuclear proliferation expert at the Stockholm International Peace Research Institute, said that to reach a deal, the West might have to let Iran continue some sort of uranium enrichment programme under specified constraints.

The United States has welcomed Russia's efforts to make progress with Iran, but it has stopped short of specific praise for the "step-by-step" proposal and said it will continue a dual approach of sanctions and the possibility of talks.

A senior Russian diplomat told Reuters on Wednesday that Moscow's Western partners supported the proposal in general, but that there were differences over details and specific steps.

However, a Western diplomat said the United States, France, Britain and Germany consider the idea of easing sanctions at an early stage to be unacceptable.

French Foreign Ministry spokeswoman Christine Fages said Iran must comply with U.N. Security Council resolutions over its nuclear programme, indicating France would continue to insist that Iran suspend all enrichment-related activities.

While the United States and Israel have not ruled out the use of force to prevent Iran from developing nuclear weapons, Russia and China have been softer on Tehran.

Lavrov said Iran's Russian-built Bushehr nuclear power plant would become fully operational in the "nearest future," but the head of Iran's atomic energy agency said in Tehran that he expected this would not happen until November or December.

Repeated delays have irritated Iran and fuelled speculation that Moscow is using the longstanding project as a lever in diplomacy over Iran's nuclear programme.