A report by the UN nuclear watchdog on Iran's nuclear program indicates that the Islamic republic is intent on developing a nuclear weapon, a US State Department spokesman said Wednesday.

"I think that, at this point, there are a lot of questions that remain to be answered," spokesman Sean McCormack said. "But those questions point in one direction, and that is that Iran is working to develop a nuclear weapon."

McCormack said the report – submitted by the International Atomic Energy Agency to the 35 members of its board of governors who will be holding an emergency meeting Thursday – "raises a number of very troubling issues that Iran has yet to address".

The report, based on a document handed over by Iranian authorities, indicates several areas where Tehran is suspected of doing nuclear work that could be military related.

It also confirms that Iran has begun research relating to enriching uranium as it prepares to actually make nuclear reactor fuel that can also be atom bomb material.

"This report … raises questions about machining the uranium into hemispheres," McCormack said. "There's only one reason why you would try to machine uranium – highly enriched uranium – into hemispheres. You do that because you want to create a nuclear weapon."

Source: Agence France-Presse