The European Union was last night attempting to salvage a hard-fought deal with Iran after Tehran insisted on exemptions to its agreed suspension of activities that could produce a nuclear weapon.
The negotiations were taking place after the International Atomic Energy Agency chief, Mohamed ElBaradei, told a board meeting in Vienna that Iran was exempting 20 centrifuges from the deal which came into effect on Monday.
The news could harden the attitude of the US which believes Iran is attempting to produce a nuclear weapon under cover of a civil programme.
But a western diplomat said the 20 centrifuges used for uranium enrichment that Iran wants to run for research purposes were "not technically significant" in the production of a nuclear weapon.
The IAEA is expected to stand by any deal hammered out by Britain, France and Germany that would define what should be covered in the suspension arrangement with Iran.
The IAEA board is to adopt a resolution today or tomorrow on what to do about Iran's nuclear programme. But as of last night, there was no mention of referring Tehran to the UN Security Council over its nuclear-related activities.Reuse content