The head of Iran's atomic energy programme said today work had begun on a plant to produce enriched uranium.
"The preliminary steps have taken place and very extensive research has already started," Mr Gholamreza Aqazadeh, head of Iran's Atomic Energy Organisation, said on state television.
The comments, which follow Iran's announcement on Sunday that it had successfully extracted uranium and planned to process the spent fuel from nuclear reactors within the country, will add to concerns about the Islamic Republic's nuclear ambitions.
Washington has accused Iran of secretly trying to develop a nuclear weapons programme. Iran insists its nuclear plans are limited to power generation and says it has invited inspectors from the International Atomic Energy Agency (IAEA) to visit its facilities.
Mr Aqazadeh said the enriched uranium plant would be built in Kashan in central Iran. The fuel would come from another facility in the central Iranian city of Isfahan, where a Uranium Conversion Facility was close to completion, he said.
Mr Aqazadeh said these plants were independent of Iran's first nuclear reactor being built with Russian help in the southern port of Bushehr and due to come on stream by early 2004.
Iran has said it is studying the feasibility of building several more nuclear reactors to meet its booming electricity demand. "Our policy is to complete the circle of fuel for plants for peaceful purposes," Mr Aqazadeh said.