ADDIS ABABA: The presidents of Sudan and South Sudan will meet for a second day Monday as pressure mounts to settle long-running bitter disputes that have brought the rivals to the brink of renewed conflict.
Former civil war foes President Omar al-Bashir of Sudan and his Southern counterpart Salva Kiir are facing the looming threat of U.N. Security Council sanctions unless they reach a deal, after they missed a Saturday deadline.
The drawn-out African Union-mediated talks in the Ethiopian capital began several months before South Sudan split in July 2011 from what was Africa's biggest nation, following an independence vote after decades of war.
Official delegations were seen Monday heading for the talks hosted by Ethiopian Prime Minister Hailemariam Desalegn in the presidential palace, alongside AU chief mediator and former South African president Thabo Mbeki.
The pair kick-started talks with a two-hour meeting late Sunday, following marathon efforts by rival delegations to bring positions closer on a raft of issues left unresolved when the South became independent last year.
Little information has filtered out about progress of the meeting, but both leaders were seen smiling and chatting as they broke the talks for the night Sunday.
"There is still optimism some form of a deal can be settled," said a Western diplomat.
Key issues include the ownership of contested regions along their frontier -- especially the flashpoint Abyei region -- and the setting up of a demilitarized border zone after bloody clashes.
The buffer zone would also potentially cut support for rebel forces in Sudan's Southern Kordofan and Blue Nile regions, where Sudan accuses Juba of supplying former civil war comrades whom Khartoum now seeks to wipe out.
The U.N. set a deadline for a deal after brutal border clashes broke out in March, when Southern troops and tanks briefly wrested the valuable Heglig oil field from Khartoum's control, and Sudan launched bombing raids in response.
U.N. leader Ban Ki-moon has called on the leaders to tackle their remaining differences, "so that their summit concludes with a success that marks an end to the era of conflict".