Today's announcement by Iran's atomic energy chief is likely to further antagonise the West.
Iran has entered the "industrial stage" of nuclear fuel production, the country's atomic chief said on Monday.
The announcement, which suggested a significant advancement for Tehran's nuclear plans, is likely to further anger the West, which fears Tehran is secretly trying to build atomic bombs.
"Today we celebrate the entry of the nuclear programme to the industrial stage," Gholamreza Aghazadeh, head of Iran's Atomic Energy Organisation told a gathering at the Natanz uranium enrichment facility in central Iran.
Iran says its nuclear programme is peaceful and has rejected U.N. demands that it halt uranium enrichment, a process that can be used to make bomb-grade material or nuclear reactor fuel.
The U.N. Security Council has passed limited sanctions on Iran after talks to end the row collapsed last year. Iran says it is open to fresh negotiations but without preconditions.
The International Atomic Energy Agency (IAEA), the U.N.'s nuclear watchdog, says it has gaps in its knowledge about Iran's plans that must be filled before it can say they are peaceful.
The IAEA is pushing Tehran to agree to let it install cameras in the underground section of Natanz to monitor Iran's work. Iran says such intrusive surveillance goes beyond its basic safeguards commitment to the IAEA. Talks continue.