This was despite Iran’s “statement of a firm, high-level commitment… and its stated willingness to accelerate the resolution of all outstanding issues,” Amano told the IAEA’s board of governors, according to the text of his speech.

The IAEA regularly inspects Iran’s nuclear facilities, but it also wants Iran to respond to allegations that its programme in the past had “possible military dimensions” — in other words that it researched how to build a nuclear bomb.

After years of Tehran rejecting these claims, progress began to be made in February, with Iran providing the IAEA with explanations on one out of 12 suspect areas and in May promising information on two more.

As reported by the INU last week, Iran however failed to do so by a mutually agreed August 25 deadline. Iran had committed to clarify questions on five issues. Iran responded to one question on time, responded to two questions belatedly. Regarding the two outstanding issues from the previous agreement Amano said Monday merely that the IAEA and Tehran has “begun discussions”. 

Iran’s envoy to the IAEA, Reza Najafi, said last week that Iran had informed the agency that the August 25 deadline would not be met and that further talks would be held in Tehran in late September.

Not answering the IAEA’s long-standing questions — including suspect activities on a military base in Parchin — could harm the chances of reaching a historic deal between Iran and world powers, experts say.

That accord would be focused on the future of Iran’s declared nuclear facilities, which Tehran says are for peaceful purposes but which Western countries fear could one day enable it to build a bomb.

New talks on this mooted agreement between Iran and the five permanent members of the UN Security Council plus Germany are due to resume in New York on Thursday, September 18 ahead of a November 24 deadline. Iranian negotiators have expressed little optimism that there could be a breakthrough during the new round of talks. 

Experts and diplomats believe that, at the current pace, the IAEA’s probe will take roughly one to two years to complete — assuming Tehran cooperates.

“At this stage I cannot say how long it will take to clarify the 12 areas…. However this is not an endless process,” Amano told a news conference in Vienna.

“With the cooperation of Iran we can clarify these issues within a reasonable timeline.”