"The negotiations between the International Atomic Energy Agency and Iran began today and are going to continue for two or three days," ministry spokesman Mohammad Ali Hosseini said in a statement carried by official media.

"The talks are focussing on P1 and P2 centrifuges," Hosseini added.

Iran has been seeking to develop advanced P2 centrifuges which are capable of enriching uranium more efficiently than the P1 technology it currently uses.

The new talks with UN inspectors came as Iranian President Mahmoud Ahmadinjad was at the United Nations in New York on a controversial visit in which he has strongly rejected US charges that his government's nuclear programme is cover for a drive to develop an atomic bomb.

Iran and the IAEA agreed a timetable last month for Tehran to provide answers to outstanding questions over its nuclear programme.

The IAEA has been investigating Iran's programme for the past four years but has so far failed to make a conclusion over whether it is peaceful or not.

Enriching uranium is normally a key component of the cycle to make nuclear fuel but in highly-enriched form the uranium could be used to make the fissile core of a nuclear bomb.

Iran has been enriching uranium to levels well below that required to make nuclear weapons.

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