Iran's stock of uranium enriched to up to 60 percent, close to weapons-grade, and has grown to well above the amount that by one definition is enough, if enriched further, for a nuclear bomb, a quarterly report by the UN atomic watchdog showed on Wednesday.

Iran's uranium enriched to up to 60 percent and in the form of uranium hexafluoride, the gas that centrifuges enrich, is estimated to have grown by 12.5 kg to 55.6 kg since the last quarterly International Atomic Energy Agency(IAEA) report issued on May 30, the IAEA report to member states seen by Reuters said.