The International Atomic Energy Agency (IAEA) has once again found discrepancies in Iran's nuclear declaration, this time in details of experiments on the separation of plutonium, which could be a sign of a bomb program.

The IAEA board of governors met in a closed session Thursday to hear a report from deputy head of the agency, Pierre Goldschmidt.

He said Tehran received sensitive technology earlier than it originally claimed and that plutonium experiments went on until the late 1990s. 

Originally Iran had submitted a declaration, which was supposed to be accurate and complete stating that the experiments ended in 1993.

For the United States, this is further proof of Iran's work on a secret nuclear weapons program, something strongly denied by Tehran.  The Iranian delegation told the board Tehran had not failed to report nuclear activities.

U.S. ambassador to the IAEA, Jackie Sanders, called on Iran to dismantle "all nuclear fuel activities" including a heavy water reactor that could be used in a civilian or military program. This would go further than the suspension of nuclear enrichment activities that Iran has voluntarily agreed to as part of a deal with European countries.

Iran says the IAEA has conducted verification inspections that went well beyond what is legally required.

The U.N. nuclear watchdog agency says there are also discrepancies in Iran's account of when it first met with black marketers to discuss nuclear technology transactions.

Much of Iran's nuclear program has come from the network once headed by a top Pakistani scientist who also assisted Libya's secret nuclear activities.

Rebecca Johnson, editor of Disarmament Diplomacy says Iran seems to be aiming for a nuclear weapons option.

"If Iran proceeds down this route it could through nuclear uranium enrichment under the current interpretation of the Nuclear Non-Proliferation Treaty develop enough low enriched uranium and if it then decided to withdraw from the treaty and enrich that uranium to a high weapons usable level of enrichment it could do that relatively easily and I think that's the real danger," she said.

Ms. Johnson thinks if Iran ever decided to go for a weapons program and withdrew from international obligations, it could be too late.

The IAEA also said it was sending a team of experts to the former Soviet republic of Georgia to trace material gone missing which could be used in a nuclear bomb.