ASMARA, Eritrea — Five Darfur rebel groups have agreed to join forces ahead of a meeting Sunday in Libya to push for a solution to the four-year conflict in the western region of Sudan.

The new coalition, calling itself the United Front for Liberation and Development, said Saturday it wanted to establish "a united front to deal with the crisis in Darfur and the Sudan; and appeal to all other movements to contribute to unity efforts."

The group has been meeting in Eritrea since late May.

More than 200,000 people have died and 2.5 million have been displaced in the Darfur region of western Sudan since 2003, when ethnic African rebels took up arms against the Arab-dominated Sudanese government, accusing it of decades of neglect.

Sudan's government is accused of retaliating by unleashing a militia of Arab nomads known as the janjaweed -- a charge it denies.

A peace agreement signed a year ago year between Sudanese President Omar al-Bashir's government and one rebel group in Darfur has been ineffective because more than a dozen other rebel factions rejected the deal and are still fighting.

The five rebels groups who agreed to unite Saturday are among more than a dozen relatively obscure splinter factions that emerged in the aftermath of last year's peace deal.

Experts say they do not represent a significant military force on the ground in Darfur. But Eritrea, Chad and Libya have been pushing for the creation of such an umbrella coalition for the rebels in the hope this could facilitate ongoing peace negotiations with Khartoum.