The Sudanese government and the southern-based rebel group have signed an agreement on resolving Africa's longest running civil war.
The agreement signed Wednesday sets the terms for a power-sharing transitional government and the status of three disputed regions in southern Sudan.
Mediators say the agreement clears the way for further negotiations on how to implement a permanent cease-fire between the government of Sudan and the Sudanese People's Liberation Army.
The Kenyan Foreign Minister, Kalonzo Musyoka, hailed the accord. He said it put southern Sudan on what he called "an irreversible path toward peace."
A 21-year conflict has claimed more than 2 million lives, mainly of civilians who died of famine and disease.
The SPLA represents the mainly Christian and Animist southerners. While the Khartoum government is controlled by Muslim Arabs.
The conflict in southern Sudan is not related to the 15-month war in the western Darfur region of the country, which the United Nations has classified as the world's worst humanitarian crisis.
The Darfur war has displaced an estimated one million people as rebels from the region, primarily black African population, fight government-backed Arab militiamen.