Addis Ababa: The African Union is ready for a controversial peacekeeping mission in Somalia but nowhere near implementing an intended 4,000 troop expansion of its stretched Darfur force, a top official said yesterday.

"African countries are willing to give any amount of troops for peacekeeping ... [but] I'm telling you, that might be impossible," peace and security director Geofrey Mugumya said of the proposed increase to the 7,000-strong AU force in Darfur.

Khartoum opposes UN entry and the AU mission's mandate ends on December 31, and the pan-African body is struggling even to rotate current battalions, let alone add the intended six more at a cost of roughly $80 million.

"Sometimes you get promises [of funds], but they are not translated into reality," he told Reuters at AU headquarters in Ethiopia, saying an Arab League pledge of $50 million to boost the Darfur mission had not yet materialised.

The AU official was more upbeat, however, about the likelihood of a Ugandan-led African peacekeeping mission in Somalia. It would be tasked with bolstering an interim government challenged by the rise of powerful Islamists.

"Ugandan forces are ready and will go if the arms embargo is lifted or modified," he said, adding that the UN Security Council was meeting in November to mull such a change, a pre-requisite for an African intervention.

The Mogadishu-based Islamists have threatened to fight any foreign troops, and Al Qaida leader Osama Bin Laden has said such an intervention would justify jihad.

But Mugumya insisted an African force would calm the situation, rather than inflame it. "What we want is to protect the Transitional Federal Government, so it does not go back to being stateless, we want to put water on the fire," he said.