"We expect their reply before July 15," Douste-Blazy said during a visit to Moscow for talks with other foreign ministers from the Group of Eight.

"It seems clear to me that Iran will say yes. Then there will be negotiations," he said.

"If the response is negative between now and July 15, then it is clear that the international community will be firm and that in particular we will continue what we have begun in the (UN) Security Council," he added, referring to discussions over potential measures against Iran.

"It is necessary to create conditions for a return to negotiations," he said.