Iran has confirmed it is installing new uranium enrichment machines to speed up its nuclear programme.
It is installing two newer and more advanced models of centrifuges used to refine uranium for large-scale testing at a research site, Foreign Ministry spokesman Ramin Mehmanparast confirmed.
"By installing the new centrifuges progress is being made with more speed and better quality," Mehmanparast said, adding the move showed Iran was being successful in its "peaceful nuclear activity".
If the more modern centrifuges are successfully introduced for production, it could significantly shorten the time needed to stockpile nuclear material.
The International Atomic Energy Agency (IAEA) has been informed about the installment of new centrifuges, Mehmanparast said.
"The agency is aware that our peaceful nuclear activities are progressing, the installment is a confirmation of the Islamic Republic's success in the nuclear field," he said.
Iran has for years been trying to develop centrifuges with several times the capacity of the 1970s-vintage, IR-1 version it now uses for the most sensitive part of its atomic activities.
The United States and its allies have accused Iran of trying to develop bombs under cover of its nuclear programme.
However Iran denies the allegation, saying it needs nuclear technology to generate electricity to meet its booming domestic demand.
Iran's refusal to halt uranium enrichment has led to four rounds of U.N. sanctions on the major oil producer, as well as tighter U.S. and European Union restrictions.
Diplomatic efforts to find a solution to Iran's nuclear dispute have stalled, after talks between Iran and six world powers over half a year ago failed to make any progress.