The governments of Sudan and newly independent South Sudan have reached a new agreement to withdraw their troops from the disputed Abyei region.

The United Nations' assistant peacekeeping chief, Edmond Mulet, says the two sides agreed in Addis Ababa Thursday to pull their forces out of Abyei between September 11 and 30.

Sudan and South Sudan had previously agreed to withdraw troops from Abyei but had not yet done so. The crisis in the region began in May when Khartoum government forces occupied Abyei.

Thursday's agreement on a pullout comes as Ethiopian peacekeepers begin moving into the region to demilitarize it.

The fate of Abyei was left undecided when South Sudan split from the north in July following a referendum on independence. A referendum was originally also planned in Abyei for the population to determine which country they wanted to belong to, but the vote was never held.

Abyei is one of several flash points between Sudan and South Sudan. Fighting has also taken place in the Sudanese states of South Kordofan and Blue Nile.