South Sudan's president Salva Kiir met Saturday with his Sudanese counterpart Omar al-Bashir in Khartoum.

The two leaders discussed some of the unresolved bilateral issues since South Sudan became an independent state July 9.

The two neighbors have yet to reach an agreement on the future of the contested oil-rich border region of Abyei. A referendum on the issue was postponed earlier this year because the sides could not agree on who was eligible to vote.

Sudanese and South Sudanese presidents are also expected to discuss oil since most of Sudan's production before the separation came from the south.

Another topic is sure to be the fighting in Sudan's Blue Nile and Southern Kordofan border area.

South Sudan has withdrawn its troops from Abyei, but Sudan refuses to leave until all planned 4,200 Ethiopian peacekeepers have arrived. Currently, only half of the Ethiopian peacekeepers are in Abyei.