Iran will continue preparing raw "yellowcake" uranium for enrichment until early next year despite a recent pledge to freeze all such activity, diplomats said.
"The Iranians have decided to continue UF4 (uranium tetrafluoride) production until the end of February," a diplomat said. The process can be used to make nuclear weapons.
UF4 is the precursor to uranium hexafluoride (UF6), the gas that is fed into centrifuges which spin at supersonic speeds to purify it for use as fuel in civilian nuclear power plants or in atomic weapons.
Iran recently pledged to freeze all activities linked to uranium enrichment as a confidence-building gesture.