Iran said on Tuesday operations had begun at two uranium mines and a milling plant and that Western opposition would not slow its nuclear work, days after talks with world powers made no breakthrough, reported Reuters.
Iran opened the Saghand 1 and 2 mines in the central province of Yazd and the Shahid Rezaeinejad yellowcake plant in the town of Ardakan in the same region to mark the country's National Nuclear Technology Day, state news agency IRNA said.
Yellowcake can be further processed into enriched uranium to make fuel for nuclear power plants, Iran's stated aim, or to provide material for atomic bombs if refined much more, which the West fears may be the Islamic Republic's ultimate goal.
Talks between Iran and six world powers held in Kazakhstan last week failed to make progress in resolving a decade-old dispute that threatens to trigger a new war in the Middle East. The powers want Iran to curb its uranium enrichment activity.
Iran denies Western accusations that it is seeking an atomic weapons capability. It often announces technical advances in its nuclear programme, but these can be difficult to verify independently, Western experts say.
Iran has for years carried out construction work at Saghand and Ardakan, and Tuesday's announcement was apparently intended to show that it is becoming increasingly self-sufficient in the production of nuclear fuel, despite tightening sanctions.
Some Western analysts, however, say Iran may be close to exhausting its supply of yellowcake - or raw uranium - and that such mining in the country is not economical.