ADDIS ABABA - South Sudanese President Salva Kiir and rebel commander Riek Machar signed a power sharing agreement on Monday, African diplomatic sources said, edging closer to a final deal to end a 15-month conflict that has ravaged the world's newest country.

Under the agreement, which the leaders signed shortly after midnight, Kiir would remain president in a new administration while Machar would be appointed vice president, two African diplomats who work for the regional IGAD bloc told Reuters in the Ethiopian capital Addis Ababa.

Seyoum Mesfin, chief mediator of the East African IGAD bloc, said ahead of the signing ceremony that the two leaders had agreed to resume talks on 20 Feb.

"(Those talks) would be final and that would lead them into concluding a comprehensive agreement to end the crisis in South Sudan," Mesfin told reporters minutes before Kiir and Machar signed the latest peace deal.

Several previous peace deals and ceasefires that accompanied the agreements were swiftly broken.