The head of the UN nuclear watchdog has said force should only be used as a last resort to resolve the dispute over Iran's nuclear programme.
Iran has denied its nuclear work is intended to develop weapons
Mohamed ElBaradei urged Iran's critics to learn the lessons of Iraq.
The French Foreign Minister, Bernard Kouchner, has suggested that the world should prepare for war over Iran's nuclear ambitions.
Mr Kouchner is meeting his Russian counterpart in Moscow, with Iran's nuclear programme topping the agenda.
No 'clear danger'
Mr ElBaradei, speaking at the general conference of the International Atomic Energy Agency (IAEA) in Vienna, insisted that any attack on Tehran should only be authorised by the UN Security Council.
"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 the country has nuclear weapons," he said.
"I do not believe at this stage that we are facing a clear and present danger that requires we go beyond diplomacy," he added.
Meanwhile, Iranian President Mahmoud Ahmadinejad has said he does not take Mr Kouchner's comments seriously.
"Media speculations are different from real words and we do not take these remarks seriously," Mr Ahmadinejad told Iran's state news agency, IRNA.
Russian Foreign Minister Sergei Lavrov and Mr Kouchner are holding talks on further UN Security Council sanctions against Iran over its uranium enrichment programme.
Russia has a UN Security Council veto over any new sanctions, and its support is seen as vital for any new approach to force Iran to end enrichment.
In an interview published in Russian magazine Vremya Novostei, Russian 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.
Tehran has warned that any new punishments could push it to stop co-operating with the IAEA.
It denies it is trying to acquire nuclear weapons, and says it wants nuclear power to generate electricity for civilian use.
The US has not ruled out a military attack against Iran to prevent it from acquiring a nuclear weapon.