VIENNA: Iran angrily stayed away Monday from a UN atomic agency forum on creating a Middle East free of nuclear weapons, amid growing tensions over Tehran's suspected efforts to develop the bomb.

Iran's ambassador to the Vienna-based International Atomic Energy Agency (IAEA) Ali Asghar Soltanieh said Tehran's decision was its "first reaction" to the body's "inappropriate" recent report on its nuclear programme.

That assessment saw the IAEA come the closest yet to accusing Iran outright of seeking to develop nuclear weapons. Iran, hit by four rounds of UN sanctions, says its activities are exclusively for peaceful purposes.

On Friday the IAEA's board of governors passed a resolution of "deep and increasing concern" submitted by the five permanent members of the UN Security Council, Germany and 12 others in light of the report.

Soltanieh said another reason for not attending the two-day forum, aimed at learning from the experiences of other so-called nuclear-weapon-free zones (NWFZ), was Israel's alleged atomic arsenal.

"The Zionist regime (Israel)... is pursuing secret nuclear activities which are worrying for the international community," Soltanieh told Iranian television channel Al-Alam.

"As long as the Zionist regime does not belong to the NPT (nuclear non-proliferation treaty) and does not cooperate with international organisations... this kind of conference is useless and cannot succeed."

Israel is widely believed to possess nuclear weapons but has never confirmed it. Unlike Iran it is not a signatory to the NPT and therefore not subject to IAEA inspectors.

IAEA member states requested in 2000 that such a forum take place but agreement on holding such a meeting remained elusive until now.

The forum comes ahead of a conference in 2012 to be hosted by Finland on ridding the powder keg region, rocked this year by Arab Spring popular uprisings in several countries, of nuclear weapons.