French Foreign Minister Philippe Douste-Blazy said on Friday that Iran's nuclear offer response was unsatisfactory, RTL radio reported.

"For the moment it is not satisfactory," Douste-Blazy said, adding that it was important to avoid escalating a conflict with Iran.

Iran presented a 21-page formal response to an incentives package offered by the five permanent UN Security Council members -- Britain, China, France, Russia and the United States, plus Germany.

In the response, it offered ideas that would allow serious talks to start immediately and asked for a timeline to implement the incentives and specifics on possible security arrangements as promised by the six countries.

Iran has been in dread of a military attack from the United States.

The UN Security Council has warned Iran of possible sanctions if it does not meet an Aug. 31 deadline to freeze uranium enrichment, a process that can lead to the production of fuel for nuclear power plants or material for warheads.

So far, the Security Council has not given their verdict on Iran's reply.

Iran is suspected by the West of trying to produce nuclear weapons under the cover of a civilian nuclear power program.

Iran, the world's fourth largest oil exporter, says it needs to enrich uranium as a peaceful, alternative energy source and has the right to do so under the nuclear Non-Proliferation Treaty.