Chief of Iran's Atomic Energy Organisation Gholam-Reza Aqazadeh announced on Wednesday that more than 5,000 centrifuges are now actively running at the country's uranium enrichment plant, the official IRNA news agency reported.
"Currently we have more than 5,000 centrifuges operating," the agency quoted Aqazadeh as telling reporters, signalling further expansion of the Islamic state's controversial nuclear activities.
Low-level enriched uranium is used to produce nuclear fuel but enrichment at higher levels makes it suitable for use in nuclear weapons, reported dpa.
The United States and its allies have demanded a suspension of Iran's enrichment activities, and the UN Security Council has passed three sanction resolutions also calling for a halt, which Tehran has ignored, insisting its nuclear programme is peaceful aimed at generating electricity.
"Suspension has no meaning at all in Iran's culture and no such a thing exists," Aqazadeh was quoted as saying.
President Mahmoud Ahmadinejad had also said in July that of 6,000 new centrifuges, 5,000 have become operational and the then deputy foreign minister, Alireza Sheikh-Attar, who is now Iran's ambassador to Berlin, said later in August that Tehran is planning to install 54,000 centrifuges.
The UN nuclear watchdog, the International Atomic Energy Agency (IAEA), has so far confirmed that about 3,000 to 3,500 centrifuges were operational at the Natanz plant. Iranian claims of the number of centrifuges often do not match IAEA reports.