In an interview published on Monday by British newspaper The Daily Telegraph, Bernard Kouchner also said he would be reluctant to back further sanctions against Iran and was focusing on the option of dialogue for the time being.

"They (Israel) will not tolerate an Iranian bomb. We know that, all of us. So that is an additional risk and that is why we must decrease the tension and solve the problem. Hopefully we are going to stop this race to a confrontation," Kouchner said.

"There is the time that Israel will offer us before reacting, because Israel will react as soon as they know clearly that there is a threat," he said.

Iran says its nuclear programme is aimed at generating electricity but Israel and numerous Western nations fear its real intention is to build nuclear weapons.

Tehran has said it would respond this week to a U.N.-drafted plan under which it would send its uranium abroad for further processing.

Foreign powers that are negotiating with Iran over the nuclear issue, including France, had said it had tentatively agreed to the plan during a Geneva meeting on Oct. 1.

But Iran's foreign minister said on Monday that another option was on the table, to buy fuel rather than send out its own. That challenges the basis of the proposed plan.

France has taken a relatively hawkish approach in the negotiations with Iran and has signalled that it would back further economic sanctions against Iran if no significant progress was achieved.

However, Kouchner said in his newspaper interview that he personally doubted that sanctions would be effective.

"Certainly, the upper people in the Iranian government, they will not suffer from sanctions. But the people of the bazaar and the people on the street, the women and the youngsters, they will certainly suffer from that," he was quoted as saying.

"There is an opposition, people are demonstrating, very courageously they were in the streets. Why are we targeting them? I don't know. We are not for the time being looking for sanctions," he said.