"That is not a conclusion we have reached. And we want to be very clear that it is our preference that Iran works with the international community ... to fulfil its obligation on inspections," she said.

Nazanine Moshiri, Al Jazeera's correspondent in Tehran, said it was "extremely important" for Iranians not to have the immediate worry of sanctions.

"They don't want a forfeit round of sanctions right now. That's why they're keen to keen continue this diplomatic track and keen to talk to the Americans at Vienna on October 19th," she said.

"And also to open up [the nuclear site of] Qom to inspections. It's a very clever move by the Iranians to continue this track."

'Very reserved'

Lavrov, for his part, said he was "very reserved" about further sanctions.

In his opinion, he said, "threats of sanctions and threats of pressure in the current situation are, in our opinion, counterproductive".

At a joint news conference with Lavrov in the Russian capital, Clinton said the two politicians had held "productive and comprehensive discussions."

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Iran says uranium enrichment is a
'non-negotiable' right

Lavrov confirmed the areas of discussion covered had included the Middle East, North Korea and Afghanistan.

Furthermore, he said negotiations aimed at replacing a key Cold War-era nuclear disarmament treaty by the end of the year had made a "substantial movement forward".

Russia and the US should work more closely on missile defence plans, Lavrov said, after Washington's recent shelving of a missile defence system in Eastern Europe ended a major dispute with Moscow.

Clinton's visit to Moscow is her first since becoming Washington's top diplomat and comes a week before international talks on a proposal to send Iranian uranium abroad for further processing.

The visit comes after Barack Obama, the US president, vowed on a visit to Moscow in July, to "reset" US-Russia relations.

Lavrov had called for "full clarification" about the new sea-based missile defence system which Obama unveiled last month to replace an earlier version, backed by his predecessor, George Bush, to deploy missile defence facilities in Poland and the Czech Republic.

'Responsible approach'

Russia had fiercely opposed Bush's plan and welcomed Obama's move to alter it as a "responsible approach".

Start, which places strict limits on the US and Russian nuclear arsenals and is seen as a cornerstone of Cold War-era strategic arms control, expires on December 5 and negotiators have been seeking to thrash out a successor agreement.

"It's been believed for a very long time that the bargaining tool, as it were, from the United States making a U-turn on the missile defence shield was for Russia to place more pressure on Iran," Neave Barker, Al Jazeera's correspondent in Moscow, said.

"There is undoubtedly now more international pressure on Russia to support US action against Tehran but we'll have to wait and see.

"Over the course of the week, we'll have a clearer idea of where Russia is likely to take its new ties with the US and undoubtedly Iran will be at the crux of that new era in relations."

Uranium enrichment

Also on the agenda was North Korea, which set off another round of short-range missile tests on Monday and, according to South Korean media reports, is poised to launch more missiles on Tuesday.

The US, Russia, China, Britain, France, the five permanent members of the UN Security Council, along with Germany (the so-called P5-plus-1 group), has demanded that Iran halt its disputed uranium enrichment programme.

The West fears the programme masks a drive for a bomb - a charge Tehran denies, saying it is only for peaceful nuclear energy.

The P5-plus-1 has been instrumental in getting the UN Security Council to adopt three rounds of sanctions against Tehran, although Russia and China have resisted tougher sanctions.