Delegates from more than 180 countries will be gathering in New York to take part in the Non-Proliferation Treaty review conference, to be held from May 2-27.

The United States and Europe believe Iran is seeking to develop nuclear weapons. But Tehran says its program is aimed at producing fuel for peaceful purposes.

Undated satellite image provided by Space Imaging/Inta SpaceTurk shows once-secret Natanz nuclear complex in Natanz, Iran, about 150 miles south of Tehran
In an agreement last year with three European countries - Britain, France and Germany - Iran decided to temporarily suspend its nuclear enrichment program: a technology that could lead to producing nuclear weapons. The United States is not involved in the talks, but backs the Europeans who are continuing their negotiations with Iran. The European Union hopes the discussions with Iran will make the suspension permanent in exchange for trade deals.

Experts are divided as to whether the talks have progressed and could eventually lead to Tehran giving up its nuclear weapons aspirations.

Graham Allison from Harvard University, who has written extensively on nuclear issues, says the fact that the talks are going on is a good sign.

"The Europeans have been more successful than one would imagine given the cards that they have to play, in which the EU three - Britain, France and Germany - have been negotiating with the Iranians about benefits that they could get if they would freeze indefinitely their work on their factories that would allow them to enrich uranium and therefore produce bombs," he said. "And to be able to get this far only by offering them economic benefits, which is all the Europeans can offer them, without the United States having entered the game, is pretty impressive."

But Henry Sokolski, Director of the Washington D.C.-based Nonproliferation Policy Education Center and a former U.S. Defense Department official, disagrees.

"The problem is, they have got into a situation where they have Iran chomping at the bit to resume enrichment activities, nibbling around the edges of their current agreement to suspend their declared activities and demanding of the Europeans that they give ever more to Iran, to compensate it for what it - that is Tehran - sees as its right to have any and all forms of nuclear energy," he explained. "This is a losing hand: Europe can probably never give enough for Iran to renunciate or give up or dismantle its uranium enrichment and soon its plutonium reprocessing activities. So the Europeans are making the best of a bad situation by arguing that so far, so good: as long as we keep them suspended, it's as good as having the program dismantled."

Mr. Sokolski says without getting the Iranians to give up their program publicly, you have to worry about what they might be doing covertly.

Daryl Kimball heads the Arms Control Association, a non-profit organization based in Washington D.C. He says ultimately, for the talks to succeed, the United States must be directly involved.

"Now the real question that we have - and it may be answered over the next few months - is whether the European Union and Tehran can reach an understanding about an indefinite moratorium or pause of Iran's nuclear activities," he said. "I think it's going to require that the Europeans and possibly the Americans, agree to normalize economic and political relations with Iran and also provide Iran some form of guarantee that Iran will be supplied with the nuclear fuel for nuclear energy production, which is what Iran says it is really interested in."

Experts point to one positive development and that is the recent agreement between Tehran and Russia concerning Iran's Bushehr nuclear reactor. Russia is helping build the facility and the accord provides for the spent fuel to be returned to Russia.

William Potter is the director for non-proliferation studies at the Monterey Institute of International Studies. He says the United States is still concerned that any nuclear assistance Russia provides to Iran could assist Tehran's nuclear weapons program.

"That being said, I think that the administration is pleased that the Russians have insisted upon the return of the spent fuel from Iran: that is fuel that could be reprocessed to produce plutonium for weapons purposes," he said. "What the United States would like to have, is a more active Russian partnership in providing incentives, as well as threatening disincentives, should Iran move in the wrong direction."

Experts say Iran's nuclear weapons ambitions will be high on the agenda when delegates from more than 180 countries meet in New York next week for a month-long review of the Non-Proliferation treaty, the legal cornerstone of non-proliferation efforts. Analysts say with Iran present, the debate could be heated.