Israeli Defence Minister Ehud Barak said on Thursday, ahead of a meeting of the UN nuclear watchdog, that he was "not very optimistic" about the prospects of strong new sanctions against Iran.

"I'm not very optimistic -- there are difficulties in mobilising will in the world. That's why we're working to convince foreign leaders to impose strong and concrete sanctions to stop Iran," Barak told Israeli public radio.

Speaking from Ottawa, where he is on a visit, Barak said that Iran's nuclear programme "is not directed solely at Israel, but against the entire world order".

"Today there is an important meeting of the International Atomic Energy Agency in Vienna, and we should not appear to be a country that whines, that is afraid, but simply stress that Iran has launched a challenge to the whole world... and the world must move," Barak said.

"No option should be taken off the table, which is also the position of the Europeans and Americans, but I think that I should not say anything more at this stage," Barak added in an interview with Israeli army radio.

The IAEA board was due to begin a two-day meeting at its headquarters in Vienna on Thursday, with Iran's nuclear programme expected to top the agenda.

After a damning report from the body that said there was "credible" information Iran was carrying out "activities relevant to the development of a nuclear explosive device," the meeting was expected to produce a resolution criticising Tehran.

But the international community, and particularly the five veto-wielding permanent members of the Security Council, remain divided over the report and how to respond to it.

Britain, France and the United States jumped on the IAEA report as justification to tighten the screws on Iran, already under four sets of UN sanctions, and additional European Union and US restrictions.

But China, which relies heavily on Iranian oil imports, and Russia, which also has close commercial ties and built Iran's only nuclear power plant, have been far more cautious.