Russia today joined the chorus of concern at the possibility of war in Iran while conflicts continued in Iraq and Afghanistan.

At a news briefing in Moscow, the Russian foreign minister, Sergei Lavrov, said: "We are worried by reports that there is serious consideration being given to military action in Iran. That is a threat to a region where there are already grave problems in Iraq and Afghanistan."

His comments, after a meeting with his French counterpart, Bernard Kouchner, followed a stark warning yesterday from the UN's chief nuclear weapons inspector aimed at the US.

"I would not talk about any use of force," Mohamed ElBaradei told reporters at the International Atomic Energy Agency headquarters in Vienna. "There are rules on how to use force, and I would hope that everybody would have gotten the lesson after the Iraq situation, where 700,000 innocent civilians have lost their lives on the suspicion that a country has nuclear weapons."

Fears of a military conflict with Iran rose a notch after comments on Sunday night by Mr Kouchner, who said: "We have to prepare for the worst ... the worst is war."

In addition, reports from Washington indicate that administration hawks led by the vice-president, Dick Cheney, are winning the argument for tough action against Tehran.

The US has accused Iran of supplying Shia extremists in Iraq with explosive devices that are taking a deadly toll on American troops.

Another flashpoint is Iran's refusal to stop uranium enrichment, a process that can lead to the development of a nuclear bomb. The US is trying to mobilise international support for further sanctions against Iran at the UN security council, but can expect Russian and Chinese opposition.

The US suspects that Iran is determined to develop a nuclear weapon under cover of its civilian nuclear programme, a charge Iran denies. While it says it is seeking a diplomatic solution, the US has not ruled out the use of force.

France, under its new president, Nicolas Sarkozy, has adopted a much tougher line on Iran, saying that a nuclear-armed Iran poses a dangerous threat to the west.

Mr Sarkozy last month called the Iranian stand-off "the greatest crisis" of current times, saying the world faced "a catastrophic alternative: an Iranian bomb or the bombing of Iran".

Mr Kouchner told reporters in Moscow that the world should not shy away from sanctions to put pressure on Iran.

"The worst thing to happen would be a war, and in order to avoid it we need to continue talks and be firm enough regarding sanctions," he said. "We have to work on precise sanctions that would demonstrate the world community's serious approach to this problem."

But Russia is trying to cool down the situation. In an interview published in the Russian magazine Vremya Novostei, the deputy foreign minister, Alexander Losyukov, said any military intervention in Iran would be a "political error" with catastrophic results.

"We are convinced that there is no military solution to the Iranian problem ... besides, it is quite clear that there is no military solution to the Iraqi problem either," he said.