IAEA visit: It's showtime for Iran's nuclear denials

With top United Nations nuclear inspectors on a three-day trip to Iran, Tehran is sending mixed messages of cooperation and defiance.

The high-profile visit from the International Atomic Energy Agency (IAEA) presents Iran with the first formal opportunity to rebut specific allegations of past weapons-related work since they were made public in an agency report in November.

The Islamic Republic has for years dismissed the documents those allegations are based upon as forgeries created by hostile intelligence agencies, aimed at besmirching a peaceful energy program. But now that talk of a US-Israeli war against Iran has gained momentum, in concert with an array of crippling sanctions, Iran says it will address those allegations.

"We are very optimistic about the outcome of the IAEA delegation'sbank and the lifeblood of its economy, its oil exports, in a bid to curb Iran's nuclear work.

Protesters turn out for IAEA arrival at Tehran airport

The head of the IAEA team in Iran says their aim is to "resolve all the outstanding issues with Iran." Those include weapons-related studies – their "systematic" nature apparently halted in late 2003, according to the IAEA – which range from high-explosives testing to reengineering the warhead of a Shahab-3 missile to fit a specific, possibly nuclear, payload.

"In particular we hope that Iran will engage with us on our concerns regarding the possible military dimensions of Iran's nuclear program," the IAEA deputy director for safeguards, Herman Nackaerts, said before leaving Vienna on Sunday.

A group of Iranians – of a type often associated with