Iran is considering plans to start building two new uranium enrichment plants from next month, with the sites concealed in the mountains to avert air strikes.
The announcement from Iran's atomic chief Ali Akbar Salehi came soon after top US General David Petraeus warned that Washington would now pursue 'pressure track' against Iran to thwart what the US says is a 'nuclear weapons programme'.
Mr Salehi said the enrichment capacities of the new sites would be similar to the existing facility in the central city of Natanz, where a defiant Tehran is refining uranium despite three sets of UN sanctions.
Last November, President Mahmoud Ahmadinejad announced Iran would build 10 new uranium enrichment plants, after Tehran was strongly rebuked by world powers for building a second enrichment plant near the Shia holy city of Qom.
Meanwhile, European nations at a meeting in Brussels today appeared divided over increasing sanctions against Iran.
Several EU states stressed that diplomacy had not run its course and requested a UN Security Council decision.
However, General David Petraeus said the US and its ally Israel had not ruled out military strikes against Iran's nuclear sites.
The US claims Iran is enriching uranium to make nuclear weapons, a charge Tehran denies.
Enriched uranium can be used as fuel to power nuclear reactors or in very high refined form to produce the fissile core of an atom bomb.
Iran is at loggerheads with world powers for not accepting an IAEA-drafted deal, which would supply it with nuclear fuel for a Tehran research reactor in return for the transfer of the bulk of its low-enriched uranium.
Tehran insists it wants a simultaneous exchange of the two materials, with the transfer taking place inside the country, a demand strongly opposed by world powers.
