VIENNA-- World powers turned up the heat on Iran to accept a UN-brokered nuclear deal, with US Secretary of State Hillary Clinton saying Tehran was at a "pivotal moment" to show it did not want to be isolated.

As Iran said it wanted a review of the proposed deal, Britain and Russia urged it to accept the offer and France warned against "delaying tactics."

Pressure on the Islamic republic increased as Iran also indicated it prefers to buy nuclear fuel supplies directly rather than send its own uranium abroad for further enrichment.

Tehran's close ally Moscow urged acceptance of the high-profile proposal which aims to apply the brakes to Iran's galloping nuclear programme.

"This is a pivotal moment for Iran," Clinton said. "Acceptance fully of this proposal would be a good indication that Iran does not wish to be isolated and does wish to cooperate.

"We urge Iran to accept the proposal... (that) they agreed to in principle," she said, adding that Gulf states were closely monitoring "the developments in Iran because they will be the ones to feel the first effects of what Iran does or does not do."

International Atomic Energy Agency (IAEA) chief Mohamed ElBaradei called on Iran to "to be as forthcoming as possible in responding soon to my recent proposal," and also appealed for all sides to make compromises.

Iran's Foreign Minister Manouchehr Mottaki, visiting Malaysia, called for a review of the proposed deal.

"We have considered this proposal, we have some technical and economic considerations on that," he told reporters.

"Two days ago we passed our views and observations to the IAEA, so it is very much possible to establish a technical commission to review and reconsider all these issues."

Mottaki added that Iran will "continue enrichment" of uranium for nuclear power stations requiring fuel.

Earlier Ali Asghar Soltanieh, Iran's envoy to the IAEA, told AFP in Vienna: "We are ready to buy the fuel from any supplier under the full surveillance of the IAEA, as we bought from Argentina about 20 years ago with the cooperation of the IAEA."

He did not clarify whether Iran was rejecting the UN draft plan, which proposes shipping Tehran's low-enriched uranium (LEU) abroad for further processing and conversion into fuel.

French Foreign Minister Bernard Kouchner said the six world powers negotiating with Iran over its nuclear fuel program would not tolerate delaying tactics.

"If the Iranian response is to stall, as it seems to be, we will not accept this," he told journalists in Paris.

World powers back the draft as they fear Tehran could enrich its existing LEU to very high levels under the pretext of making fuel for a Tehran reactor, and use it to produce atomic weapons.

Tehran denies it wants a nuclear bomb.

Soltanieh said Iran is ready for another meeting in Vienna to discuss the technical details of acquiring nuclear fuel.

Iran has delayed signing the UN-drafted deal amid opposition from some leaders who suspect the US-backed proposal will ultimately lead to the suspension of Tehran's uranium enrichment work.

Enrichment is the most controversial aspect of its nuclear project as the enriched material can be used both to fuel civilian reactors and also to make the core of an atomic bomb.

Mottaki said Iran still has three options for obtaining the fuel it needs: buying directly from other nations, further enriching LEU on its own, or having the fuel processed by another country.

Britain and Russia demanded that Iran give a prompt response to the UN-drafted deal, British Foreign Secretary David Miliband said in Moscow.

"We both want to see a prompt response from the Iranian regime in respect to the Tehran research reactor proposal," he told a joint news conference with his Russian counterpart Sergei Lavrov.

Moroccan Foreign Minister Taieb Fassi Fihri urged Tehran to respect international conventions so that "peace can reign in this region."