MOSCOW – France’s foreign minister appeared today to soften his weekend warning of war with Iran if it develops nuclear weapons, emphasizing instead the need to “negotiate, negotiate, negotiate without respite.”

In the wake of Foreign Minister Bernard Kouchner’s warning, a top Russian official said that bombing Iran would lead to “catastrophic consequences.”

Mr. Kouchner also had said that European leaders were considering their own economic sanctions against Iran over its refusal to halt the enrichment of uranium in its nuclear program.

Mr. Kouchner, who is on his first trip to Moscow as France’s top diplomat, on Sunday said “we must prepare ourselves for the worst” if Iran obtains nuclear weapons, and he specified that could mean a war.

He told the French newspaper Le Monde that his comments were aimed at “drawing attention to the gravity of the crisis.” Yesterday, French Prime Minister Fillon sought to play down Kouchner’s comments, saying “France’s role is to lead the way to a peaceful solution.”

Iranian President Ahmadinejad today shrugged off Mr. Kouchner’s warning of war, saying: “We do not take these threats seriously.”

After meeting with Russian Foreign Minister Sergey Lavrov, Mr. Kouchner said he meant to say that war would be “the worst thing to happen.”

“Everything must be done to avoid war. It’s necessary to negotiate, negotiate, negotiate without respite,” he said.

Speaking on Ekho Moskvy radio after the talks with Mr. Lavrov, Mr. Kouchner said he never called for a war against Iran and was misinterpreted by media.

“We have to talk to Iranians. … I can see that it’s the best way,” he said through a Russian interpreter. “It’s not true that I desire war in Iran.”

Mr. Lavrov warned against the use of force in Iran and against unilateral sanctions for its nuclear program.

“We are seriously concerned about increasingly frequent reports that military action against Iran is being seriously considered,” Mr. Lavrov said. “The result of it for the region already facing grave problems in Iraq, Afghanistan and elsewhere is beyond conjecture.”

“We are convinced that no modern problem has a military solution, and that applies to the Iranian nuclear program as well,” he added said.

Mr. Kouchner said it was necessary “to work on precise sanctions that would show our seriousness and interest that we attach to a peaceful solution of this problem in line with the international norms.”

Diplomatic officials, speaking on condition of anonymity because of the sensitivity of the information, said the sanctions could target Iran’s credit, insurance and financial sectors.

Mr. Lavrov criticized the idea of unilateral sanctions by the European Union or America.

“If we agreed to work collectively, and that is represented in collective decisions made by the U.N. Security Council, then what purpose would unilateral sanctions have?” he said.

Mr. Lavrov’s statement reflected a rift between Russia and America and other Western nations that have pushed for tougher sanctions to persuade Iran to drop its uranium enrichment effort. American officials have said repeatedly that all options including military strikes are on the table, but put the emphasis on diplomacy and economic levers.

He signaled Moscow’s opposition to a third round of U.N. sanctions, praising an agreement the International Atomic Energy Agency reached with Iran aimed at resolving outstanding issues.

“We believe that the Security Council should not be pressured to step outside the framework of support for the IAEA,” Mr. Lavrov said.

America, its European allies and other world powers suspect Iranian authorities of seeking nuclear weapons, although Iran insists its atomic activities are aimed only at producing energy.

Negotiations and two sets of Security Council sanctions have failed to persuade Iran to stop its program for uranium enrichment, a process that can produce fuel for nuclear power plants as well as material used in atomic weapons.

French Foreign Ministry spokeswoman Pascale Andreani, asked about the prospects for agreement on a third resolution, said, “Next week in New York there will be discussions to try to have a resolution. If in the framework of the U.N. things are not sufficient, we will act in the European framework.”

French President Sarkozy is seen as taking a somewhat tougher line on Iran than his predecessor Jacques Chirac, and he is also seen as more friendly to America.

Russia, which has close ties to Iran and is building its first nuclear power plant, has repeatedly warned that overly harsh punishment for Iran could be counterproductive. Along with China, it has forced the U.S. and other Security Council members to water down sanctions.

Mr. Lavrov said that international negotiators should offer Iran some incentives in economic and other areas to help achieve progress in nuclear talks, adding that a settlement of the North Korean nuclear problem could serve as a model.

Russia has expressed frustration with Iran over its refusal to halt uranium enrichment, but has repeatedly warned that military action would be a disaster.

“Bombing Iran would be a wrong step leading to catastrophic consequences,” Deputy Foreign Minister Alexander Losyukov said in an interview published today in the daily Vremya Novostei.

Mr. Losyukov said Iran should “act more openly, demonstrate more goodwill” in order to assuage Western concerns, but he suggested Russia has little power to sway Tehran.

“We can only express our opinion. Iran has its own considerations from which it proceeds from,” he said.