TEHRAN - Iran on Friday failed to accept a U.N.-drafted plan for it to cut a stockpile of nuclear fuel that the West fears could be used for weapons, instead calling for responses to its own proposal.

The deal, proposed by the International Atomic Energy Authority (IAEA), has already been approved by the other parties -- the United States, Russia and France.

By offering its own proposal, of which no details were available, Iran appeared to be following a well-tested strategy of buying time to avert a threatened tightening of international sanctions.

Now we are awaiting a positive and constructive response on Iran's proposal from the other party on providing nuclear fuel for Tehran's reactor, Iranian state television quoted a member of Iran's negotiating team, who attended nuclear talks in Vienna this week, as saying.

The other party is expected to avoid past mistakes in violating agreements ... and to gain Iran's trust, the unnamed official said.

Western diplomats said the IAEA plan, which has not been made public, would require Tehran to send 1.2 tons of its known 1.5-tonne stockpile of low-enriched uranium (LEU) to Russia and France by the end of the year.

There it would be further enriched, in a way that would make it hard to use for warheads, and returned to Iran for use in a Tehran reactor that makes radioactive medical isotopes.

The deal would test Iran's stated intention to use enriched uranium only for peaceful energy.

It would also buy time for broader talks on world powers' ultimate goal: that Iran allay fears that it has a secret nuclear weapons program by curbing enrichment, in return for trade and technology benefits.

U.S., RUSSIA AND FRANCE ON BOARD

Diplomats said the United States and France had confirmed their acceptance of the draft accord in notes sent to the IAEA, the U.N. nuclear watchdog.

On Friday, Russian Foreign Minister Sergei Lavrov added:

We agree with these proposals and we are counting on not only Iran but all the other participants of the negotiations to confirm their readiness to implement the proposed scheme.

IAEA Director-General Mohamed ElBaradei hammered out the draft in three days of consultations in Vienna with the four nations' delegations and gave them until Friday to seek approval from their capitals.

The deal would cut Iran's LEU stockpile below the threshold that could yield enough fissile material for one nuclear weapon if it were refined to 90 percent purity.

For Iran, it would supply a medical reactor whose fuel stocks will run out in about a year.

After further processing the LEU, Russia, subcontracting with France to skirt Tehran's objections to dealing directly with Paris, would send the material on to the French, who would convert it into special fuel plates.

Iran's envoy hinted after the Vienna talks ended that his government might seek amendments to the plan.

The Islamic Republic says its nuclear energy program is only for producing electricity, but it is years away from having any nuclear power plants that would use LEU.

Shortly before the remarks carried by Iranian state television, a senior developing nation diplomat with good contacts to the Iranians told Reuters:

I have a feeling Iran will ask for more time to decide, and ask for changes...

I believe they will prefer to stagger the shipments of LEU abroad, rather than in one lump amount. They will not want to lose much of their main bargaining chip with negotiations pending on broader strategic issues in the nuclear file.

Iran has repeatedly rejected U.N. and IAEA calls on it to curb enrichment or grant unfettered U.N. inspections, meant to verify that it is not trying to develop nuclear weapons.

Six world powers will press Iran on those points at further talks at senior foreign ministry level, planned soon.

(Additional reporting by Sylvia Westall; Writing by Mark Heinrich; Editing by Kevin Liffey)

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