World powers meeting in Vienna to discuss global atomic issues have criticized Iran for proposed moves this week to accelerate its capability to produce nuclear fuel.

Britain, China, France, Germany, Russia and the United States expressed their concerns in a joint statement Thursday to a meeting of the International Atomic Energy Agency's 35-member board of governors.

The allies said IAEA chief Yukiya Amano sent a message to Iran's Atomic Energy Organization raising concerns about “possible military dimensions” of Iran's controversial nuclear program. Tehran says its nuclear ambitions are peaceful.

The U.S. ambassador to the IAEA, Glyn Davies, said Iran's move was “the most recent brazen example of (Iran's) deepening non-compliance” with international demands.

Iran is being sanctioned by the West for its controversial nuclear development,

Iran's nuclear chief said Wednesday that the country will move its production of higher enriched uranium to a new site, while also tripling its production capacity for nuclear fuel.

Iran revealed the existence of the new facility in 2009, triggering outrage from Western nations that suspect Iran is enriching uranium to make nuclear weapons.

On Tuesday, Iranian President Mahmoud Ahmadinejad rejected a report from the U.N.'s watchdog agency that said Tehran may have carried out nuclear work with possible military purposes.

Mr. Ahmadinejad said the report “lacks legal credibility” and that comments made by the chief of the International Atomic Energy Agency would have no bearing on Iran's nuclear activities.