Gholam Reza Aghazadeh addresses the media following talks with IAEA Director General Mohamed ElBaradei, in Vienna, 24 Jul 2008

Iran's atomic energy chief says he hopes international negotiations on Iran's nuclear program could start based on proposals made by Iran and six major world powers.

Gholam Reza Aghazadeh - who is also Iran's vice president - Thursday said he is "very hopeful" that the two sides' different positions will merge, allowing for substantial negotiations.

Aghazadeh made his comments after meeting with the International Atomic Energy Agency chief Mohamed ElBaradei in Vienna. The IAEA says Iran is withholding details on its sensitive nuclear activities.

On Wednesday, Iranian President Mahmoud Ahmadinejad vowed his country will continue to pursue nuclear technology despite the efforts of what he called oppressive powers.

Germany and the five permanent members of the United Nations Security Council - Britain, France, Russia, China and the United States - gave Iran two weeks to respond to an incentives package discussed Saturday at talks in Geneva.

But Thursday, Russian Foreign Minister Sergei Lavrov told reporters that Moscow is opposed to setting a deadline for Iran.

The closed-door talks in Geneva were the first to be attended by a senior U.S. envoy, Undersecretary of State William Burns.

Until now, the Bush administration has insisted on shunning nuclear talks with Iran until it stops enriching uranium.

Iranian and European Union negotiators have agreed to meet again in two weeks for more talks.

Earlier this week, U.S. Secretary of State Condoleezza Rice said Iran could face more sanctions if it does not suspend uranium enrichment.

The United States and its Western allies have accused Iran of working to produce a nuclear weapon.  Iran says its nuclear program is peaceful. 

Highly enriched uranium can be used to build a nuclear weapon. 

Some information for this report was provided by AFP.