Davos: The UN nuclear chief said on Thursday that Iran should fully disclose its nuclear programmes at the same time the US starts dialogue with Tehran without preconditions. Iran's foreign minister said President Barack Obama must declare how his policies will differ from former President George Bush's.

The manoeuvring over possible US Iranian dialogue came as Mohammad Al Baradei welcomed Obama's statements that the new US administration was willing to talk to Iran after the Bush administration's refusal to deal with Tehran.

In an interview on Tuesday, Obama condemned Iran's threats to destroy Israel and its alleged pursuit of nuclear weapons, but added: "It is important for us to be willing to talk to Iran, to express very clearly where our differences are, but where there are potential avenues for progress."

"That is the way to go," Al Baradei said at the World Economic Forum in Davos. "It is long overdue." "Iran should answer technical questions from the IAEA and the dialogue should start without preconditions," Al Baradei said in the presence of Iran's Foreign Minister Manouchehr Mottaki.

Al Baradei, who heads the International Atomic Energy Agency, went further than the UN Security Council - where the US has veto power. The council has demanded in several resolutions that Iran halt uranium enrichment as a condition for talks on its nuclear program.

Mottaki refused to say whether his government would engage the Obama administration or answer all questions from the IAEA. Instead, he said, Obama "should say which Bush policies he disagrees with," he should apologise for the US bombing of Hiroshima and Nagasaki in World War II, and his administration should stop talking to the world and instead listen.