IAEA "frustrated" by Iranian coverup of nuke work

From Radio Netherlands:

The head of the UN atomic agency hit out Monday at Iran's refusal to address allegations of nuclear weapons research and called on Tehran to allow access to a suspect military site "without further delay".

"Despite the intensified dialogue between the Agency and Iran since January 2012, no concrete results have been achieved so far," Yukiya Amano said at the start of an International Atomic Energy Agency board meeting.

"This is frustrating because, without Iran's full engagement, we will not be able to start the process to resolve all outstanding issues, including those involving possible military dimensions to its nuclear programme.

"We consider it essential for Iran to engage with us without further delay on the substance of our concerns," Amano said, according to the text of his speech released by the Vienna-based IAEA.

Amano also said that activities at the Parchin military base near Tehran, where Iran is accused of having carried out weapons research and of removing evidence in recent months, "will have an adverse impact on our ability to undertake effective verification there".

Activities spotted at Parchin by satellite "further strengthen our assessment that it is necessary to have access to the location at Parchin without further delay in order to obtain the required clarifications," Amano said.

So what's the level of "frustration" that constitutes a red line? A mushroom cloud?