Sudan's president has agreed to pull northern troops out of the disputed Abyei border region before the south secedes on 9 July.
Fighting in the border states of Abyei and Southern Kordofan has raised fears of a return to full-blown conflict.
The border's exact position has yet to be defined.
Khartoum seized control of Abyei on 21 May, provoking an international outcry and complicating talks over other sensitive issues such as how to divide oil revenue and how to split national debt after secession, opted for in a January vote.
President Omar Hassan al-Bashir, who had previously refused to withdraw troops from Abyei, was in the Ethiopian capital of Addis Ababa to meet the south's President Salva Kiir to discuss the disputed region and other unresolved issues.
A diplomat confirmed Mr Bashir had agreed to the troop withdrawal and the deployment of Ethiopian peacekeepers.
Tens of thousands of people fled fighting and looting after northern tanks and troops entered Abyei's main town.
The occupation followed an attack on northern troops and UN peacekeepers that was blamed on southern forces.
Ethiopia has said it would consider sending peacekeeping troops to the region if both Khartoum and Juba requested them.
