Russia rejected talk for now of sanctions against Iran and France warned on Friday against conflict with Tehran, raising doubts whether it will face swift penalties if nuclear work is not halted by an August 31 deadline.
Responding to an offer of economic incentives to stop enriching uranium, Iran hinted to six world powers on Tuesday it could rein in its programme as a result of talks to implement the package - but not as a precondition as they demand.
The reply seemed tailored to crack the brittle united front of four Western powers and Russia and China who agreed the UN deadline. The West sees Iran's nuclear drive as a looming threat to peace. Russia and China, key trade partners of Iran, do not.
"I know of no instances in world practice and previous experience in which sanctions have achieved their aim and proved effective," Russian Defence Minister Sergei Ivanov told reporters during a trip to Russia's far east.
"Moreover, 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. Russia stands for further political and diplomatic efforts to settle the issue."
Ivanov is seen as close to President Vladimir Putin.
Washington has said the six powers will move quickly to adopt sanctions if Iran disregards the deadline. Britain, Germany and France have been less conclusive in public.
Russia and China, both trade partners of Iran, have been unwilling and could veto sanctions in the Council. Underlining the confusion, EU foreign policy chief Javier Solana said he expected new talks in days with Iran's chief nuclear negotiator Ali Larijani "to get clarification (on Iran's response) and see how we can move the process forward".
Solana said Iran's reply, a document of more than 20 pages, contained "new elements" about which he would like to talk. US, French and German leaders said Iran's 21-page response to the incentives offer was unsatisfactory because it did not specifically agree to stop purifying uranium. Iran says its nuclear ambitions are limited to power production.
Asked about Russia's rejection of sanctions for now, State Department spokesman Gonzalo Gallegos said there were several days before the UN deadline and a lot could happen.
"This is diplomacy. We are going to be working together in consultation with them (Russia). The group (P5+1) will come together and we will make some decisions," said Gallegos. French President Jacques Chirac, speaking after a meeting with German Chancellor Angela Merkel in Paris, said Iran's response was "ambiguous".
"For the moment, it (the Iranian response) is not satisfactory," French Foreign Minister Philippe Douste-Blazy said on RTL radio, but added it was important to avoid escalating conflict with Iran and the Muslim world.
"The worst thing would be to escalate into a confrontation (between the West and) Iran on the one hand, and the Muslim world with Iran. That would be the clash of civilisations that France today is practically alone in trying to avoid," he said.
US and British forces that overthrew Iraq's Saddam Hussein in 2003 are now mired in an insurgency. Israel recently waged an inconclusive war with Lebanon's Hizbollah guerrillas. Both conflicts are widely seen to have strengthened Iran.
British UN Ambassador Emyr Jones Parry said: "On Iran, I don't think I would expect very much imminently in the Council."
He told reporters in New York that the Council was awaiting a UN nuclear watchdog report due on August 31 that will certify whether Iran has stopped enrichment-related activity or not. "Once we get that, we then need to discuss the way forward. But we need to give a measured consideration to what has been sent to us by Iran - quite clearly something which is short of what the Council is looking for. "So we need to think carefully about how we respond to that," he added, pointedly avoiding comment when asked whether London was working on a sanctions resolution.