Major powers have closed ranks to increase pressure on Iran to address fears about its atomic ambitions, and the UN nuclear chief said it was his duty to "alert the world" about suspected Iranian efforts to develop atom bombs.

The six powers involved in diplomacy on Iran -- the United States, Russia, China, France, Britain and Germany -- overcame divisions exposed by a hard-hitting UN nuclear report on Iran last week and presented a united front towards Tehran.

They hammered out a joint resolution in intense negotiations and submitted it to the 35-nation board of the International Atomic Energy Agency (IAEA), a Vienna-based UN
body, which is expected to debate and vote on it on Friday.

But it will not satisfy those in the West and in Israel, Iran's arch-enemy, who had hoped IAEA head Yukiya Amano's document would trigger concrete international action to rein in Tehran, such as an IAEA referral of its case to the UN Security Council.   

Last week's IAEA report, which assessed that Iran has been conducting research and experiments geared to developing a nuclear weapons capability, has stoked tensions in the Middle East and raised a clamour in Western capitals for harsher sanctions against the Islamic Republic.   

In November 2009, IAEA governors including Russia and China rebuked Iran for building a uranium enrichment plant in secret.
Iran rejected that vote as "intimidation."    

There has been concern that if the powers cannot settle their differences over how to nudge Iran into serious nuclear negotiations, then Israel, which feels endangered by Iranian nuclear aspirations, will attack it.   

Israel is widely believed to have the Middle East's only nuclear arsenal to deter numerically superior enemies, but has never confirmed or denied it.

Amano stressed the need for Iran to engage in serious talks to clarify issues in his report and said he wanted to send a high-level mission to the country to tackle increasing concerns about the nature of its nuclear activities.

"It is clear that Iran has a case to answer," Amano told a news conference on the sidelines of the board meeting. "We have to alert the world before nuclear proliferation actually takes place."    

Iran says it is enriching uranium only for nuclear power plants, not weapons, dismissing the intelligence information in the IAEA report obtained mainly from Western states as fabricated, and accusing the IAEA of pro-Western bias.

Amano said agency experts had examined the information carefully and put together a "clear, coherent and consistent picture" about Iran's activities.   

He said he had written to the head of Iran's Atomic Energy Organisation, Fereydoun Abbasi-Davani, this month to suggest the visit, which would air issues raised by the IAEA report.   

Amano said he hoped a "suitable date" could be agreed soon for his team's visit to Iran, which permits IAEA inspections of declared nuclear sites but since 2008 has stonewalled an agency investigation into "alleged studies" applicable to atom bombs. - Reuters