The United Nations and the African Union are meeting in Libya to discuss how to advance peace talks for Sudan's Darfur region.

Representatives from more than a dozen nations have joined the two-day conference in Tripoli, which began Sunday.

The U.N. envoy for Sudan, Jan Eliasson, and his AU counterpart, Salim Ahmed Salim, urged delegates to help create the conditions for successful peace talks between Sudan's government and Darfur rebels.

On Saturday, five rebel groups in Darfur region formed a new alliance to present a united front for peace negotiations with the government.

The five groups, calling themselves the United Front for Liberation and Development, urged other rebels groups to join them.

Before the merge, there were at least 12 rebel groups in Darfur. One faction signed a peace deal with the government last year, but the agreement has done little to stop the fighting in Darfur.

Last month, Sudan agreed under intense international pressure to allow a combined United Nations-African Union peacekeeping force numbering around 20,000 troops into Darfur.

The current AU force of 7,000 in Darfur has been ineffective in stopping widespread violence.

Four years of fighting in Darfur has left more than 200,000 people dead and some two million displaced. Sudan's government is accused of arming Arab militias blamed for many atrocities in the region. Sudan denies the charge.

Some information for this report was provided by AFP, AP.