World powers are ready to respond to Iran's call for talks over its nuclear ambitions but only if it first suspends uranium enrichment.

Iran handed over its response to an incentives package offered by six nations on Tuesday, saying it offered ideas that would allow serious talks to start immediately. The West has in the past said such calls for talks were a stalling tactic.

"As we have always said... a return to the negotiating table is tied to the suspension of uranium enrichment," French Foreign Minister Philippe Douste-Blazy told a news briefing.

There has been no sign Teheran agrees to this precondition, which it has previously dismissed as unacceptable.

One EU diplomat earlier said Iran had ruled out halting enrichment before talks in the 21-page reply "but indicated that it might be open to accept suspension in the course of negotiations."

The Washington Post quoted unidentified officials from countries involved saying Iran was willing to consider halting its atomic programme but not as a precondition for negotiations.

"In the reply, although (the West) has taken destructive measures, Iran has tried to create new opportunities for resolving the issue," senior Iranian nuclear official Ali Hosseinitash told Iran's media.

Douste-Blazy described the reply as "a very long, complex document" and said the six powers would decide in a few days what to do in the Security Council.

European Union foreign policy chief Javier Solana said the reply "requires a detailed and careful analysis."