The head of the UN's atomic watchdog has urged Iran to cooperate with a team of inspectors heading to Tehran, after a recent damning report on the Iranian nuclear program.

International Atomic Energy Agency chief Yukiya Amano told AFP that the organization’s previous efforts to check Iran's claim its nuclear program has only peaceful purposes had been hampered by "a lack of cooperation".

"We hope they will take a constructive approach. We hope that there will be substantial cooperation," Amano said on Friday.

An IAEA report in November highlighted a range of areas which had raised suspicions that Iran was pursuing the development of nuclear weapons, despite its repeated denials. It detailed 12 suspicious areas such as testing explosives in a steel container at a military base and studies on Shahab-3 ballistic missile warheads.

Amano said it was too early to say definitively that Iran was pursuing a nuclear weapons program.

But he added: "We have information that indicates that Iran has engaged in activities relevant to the development of a nuclear explosive device."

"We are requesting that Iran clarifies the situation. We proposed to make a mission and they agreed to accept the mission. The preparations have gone well but we need to see what actually happens when the mission arrives."

UN chief Ban Ki-moon said the onus was on Tehran to prove its good intentions to the inspectors, who will be visiting Iran from Sunday to Tuesday.

"There is no other alternative to addressing this crisis than peaceful resolution through dialogue," Ban told reporters in Davos.

Iran's President Mahmoud Ahmadinejad has insisted that Tehran is not dodging negotiations and was ready to sit down with world powers Britain, China, France, Russia, the United States, and Germany for talks.