The U.N. nuclear watchdog says Iran has further increased its stockpile of uranium enriched to near weapons-grade levels.

Iran has increased its stockpile of highly enriched uranium by 50 per cent, according to the UN’s nuclear watchdog, raising the stakes even as the country holds talks with the US to resolve its nuclear stand-off with the west.

Iran manufactured a record volume of uranium enriched just below the levels needed for nuclear weapons, complicating efforts to negotiate a peaceful resolution to international concerns over the Islamic Republic’s atomic ambitions.