The United Nations is readying contingency plans to deploy a quick-reaction force to take over from cash-strapped African Union peacekeepers in Sudan's troubled Darfur province, UN chief Kofi Annan said Thursday.
If requested, Annan said the UN force would be mobile and ideally have tactical air support.
"We have started contingency planning to be ready if and when the decision is taken for us to go in," Annan told reporters.
He spoke as the African Union said it may be forced to hand over its peacekeeping mission in Darfur to the UN if international donors fail to plug a funding shortfall.
A report presented to the pan-African body's Peace and Security Council said the AU Mission in Sudan (AMIS) could not be sustained beyond March without a huge infusion of cash and that the operation might have to be turned over to the United Nations.
Annan said that if the UN were to go into Darfur, it would field "a different force structure".
He noted that given the size of Darfur -- about three-quarters the size of Texas or slightly smaller than France -- any UN force "has to be mobile, has to have tactical air support, must have helicopters and the ability to respond very quickly."
The UN chief said such a UN peacekeeping force would "need very sophisticated equipment, (and) logistical support" with the emphasis "on air mobility".
He said he would turn for help to governments with such capability if the UN was given the mandate.
Annan said AU Commission chairman Aplha Omar Konare indicated to him that the AU force would want to stay for another nine to 12 months "provided the donor community gives them the necessary resources and the logistical support."
"The international community cannot allow that situation to go on unaddressed and in all likelihood will have to look at other options, including possibly the UN working with the AU to redress the situation," he added.
In December, the AU said it needed over 130 million dollars in new contributions to meet the 465 million dollars (387 million euros) it needs for AMIS operations in the current financial year that ends in May.
Noting that the last donors conference for the AU mission took place last May, Annan said the time was now ripe for a "follow-up meeting to see what donors are going to do to assist the AU in this difficult task."
AMIS, financed mainly by the European Union, the United Nations and the United States, currently has some 7,800 personnel, including peacekeepers and observers, in Darfur, where as many as 300,000 people have been killed and more than two million displaced in three years of conflict.
Annan meanwhile said both the Khartoum government and Darfur rebels were contravening their 2004 ceasefire agreement.
He urged Darfur's two rebel groups -- the Sudan Liberation Movement and the Justice and Equality Movement -- to take the current peace negotiations in Abuja, Nigeria "very seriously".
Tanzania's UN envoy Augustine Mahiga, the security council president for January, said a council meeting on Sudan scheduled for Friday would explore how to "energize the Abuja peace process" and how to transfer the peacekeeping operation from the AU to the UN "without creating a gap".
He also said there was a need for a council resolution for a new UN response to Darfur in the political, military and humanitarian fields.
UN agencies have said Darfur is the world's worst humanitarian crisis with reports of rampant rapes, extrajudicial killings and other atrocities.
War broke out in Darfur in early 2003 when rebel groups began fighting what they say is the political and economic marginalisation of the region's black African tribes by the Arab-led regime in Khartoum.