IAEA has new info on alleged nuclear weapons work by Iran

IAEA has new info on alleged nuclear weapons work by Iran: "IAEA director general Yukiya Amano had written to Iran's vice president and head of its atomic energy body, Fereydoun Abasi, 'reiterating its concerns (and) expressing the importance of Iran clarifying these issues,' according to the report.

But Tehran has not yet responded, the official said.

Nevertheless, Amano's letter 'makes it clear that we're very concerned and that Iran should engage with us,' he said.

The IAEA calculated that Iran's stockpile of low-enriched uranium in the main branch of its Natanz uranium enrichment plant had now reached 4,105 kilogrammes.

Uranium enrichment is the most controversial part of Iran's nuclear activities because it can be used not only to generate nuclear fuel, but also to produce the fissile material for a nuclear bomb.

Tehran is under four sets of UN sanctions for refusing to halt such sensitive work.

But the Islamic republic remains defiant and has even started work on a second uranium enrichment facility at Qom.

In February, Tehran had said it planned to begin feeding nuclear material into cascades by the summer. But as of May 21, no uranium-enriching centrifuges had been introduced to the site, the IAEA said."