At its nuclear facility in Natanz, Iran estimated that between November 23 and August 6, it produced 995 kilograms (2,194 pounds) of low enriched uranium, which can be used as fuel for nuclear reactors or, if enriched further, for nuclear weapons, as many governments fear.

Iran has produced a total of 2,803 kilograms (6,180 pounds) of low enriched uranium since the start of operations in 2007, according to the confidential report, which was obtained by CNN.

The report listed developments to Iran's nuclear programme since the last report in May.

Iran denies that it is enriching uranium for non-peaceful purposes.

In its report, the IAEA said that the destination of the nuclear fuel was less certain.

Iran must cooperate more with the agency to clarify the intent of its nuclear program, including providing access to all sites, equipment, persons and documents requested by the agency, the report said.

According to the IAEA report, Iran has started the enrichment of uranium up to 20 percent at Natanz.

Last month, the United States extended sanctions against Iran, saying it was targeting a number of Iranian businesses and groups accused of helping organizations such as Hezbollah, Hamas and the Taliban.