By Hasham Kalantari and Hossein Jaseb
Top atomic watchdog arrives in Tehran to investigate claims of weapons aspirations.
The UN nuclear watchdog's top investigator arrived in Tehran on Monday to press Iran for answers to Western intelligence which suggested it covertly studied how to design atomic bombs.
Iran's official IRNA news agency said Olli Heinonen, during a two-day visit, would meet Javad Vaeedi, deputy head of the Islamic republic's Supreme National Security Council.
It quoted an unnamed Iranian official as saying his visit was intended to "advance cooperation" between Iran and the International Atomic Energy Agency (IAEA), the UN body seeking to clear up suspicions about Iran's disputed nuclear ambitions.
Last week, US President George W Bush and British Prime Minister Gordon Brown pledged a united effort to prevent Iran from developing a nuclear bomb, possibly by expanding sanctions.
Iran says its nuclear programme is a peaceful drive to produce electricity so that the world's fourth-largest crude exporter can sell more of its oil and gas abroad. It has been hit by three rounds of limited UN sanctions since 2006.
Heinonen raised a diplomatic stir in February with a presentation that indicated links in Iran between projects to process uranium, to test explosives and to modify a missile cone in a way suitable for a nuclear warhead.
Iran has dismissed the intelligence as baseless, forged or irrelevant. But the IAEA wants substantive explanations to wind up a long inquiry into Iran's secretive quest for nuclear power.
IAEA Director Mohamed ElBaradei has said the world "needs to make sure Iran did not have a weapons programme".
The Iranian official quoted by IRNA said Tehran had presented its "evaluation" of the issue to the UN agency but did not rule out that it would be discussed with Heinonen.
World powers are considering enhancing a package of trade and other incentives for Iran if it stops enriching uranium, which can be used as nuclear fuel or provide material for bombs.
But Iran has rejected halting its nuclear drive and says it is working on its own proposals to help defuse the row. (Reuters)