UN inspectors gave Libya high marks yesterday for working with them as they took up Tripoli's surprise invitation to inspect Libya's atomic weapons programme for the very first time.

"Libya has shown a good deal of cooperation, a good deal of openness," said Mohamed ElBaradei, the head of the International Atomic Energy Agency (IAEA).

He led a team of inspectors invited to the North African country to see how far it had progressed toward developing a bomb and to make sure it went no further.

In a shock move following months of secret talks with US and British officials, Libya said this month it was abandoning efforts to obtain nuclear, chemical or biological weapons.

Before leaving Libya yesterday, Dr ElBaradei met the country's leader, Muammar Gaddafi, who reiterated his commitment to eliminating weapons of mass destruction.

Libya had also agreed to sign the Additional Protocol to the international nuclear Non-Proliferation Treaty, allowing more intrusive snap inspections.

"Libya committed today to act as if the protocol was in force," ElBaradei told reporters.

After Libya's sudden renunciation of banned weapons programmes, US President George W. Bush - who has made tackling proliferation of such weapons a top priority - promised to reward Libya with "far better" US relations.

Dr ElBaradei said Libya's decision to come clean about its weapons programmes would be rewarded.

"There are talks now of mainstreaming (Libya's) relations with the US, with Europe," he said.

"(Gaddafi) emphasised that Libya is looking at a different chapter in its relations with the international community, with the West. He put a lot of emphasis on the importance of international assistance for Libya," Dr ElBaradei told Reuters.

But a senior US official warned the IAEA against taking credit for Libya's new policy, saying the UN body had completely missed its weapons programme and Dr ElBaradei's trip was partly a damage control exercise and a publicity gimmick.