South Sudan's president is set to travel to Khartoum on Saturday for his first visit to the north since the south declared independence July 9.

Government officials say President Salva Kiir will meet with Sudanese President Omar al-Bashir to discuss several unresolved matters, including oil revenue sharing and border disputes.

The neighboring countries disagree on the future of the oil-rich Abyei region on their border.

At the United Nations in New York on Thursday, the world body called on both countries to comply with an agreement calling on Khartoum and Juba to withdraw their forces from the contested region.

U.N. peacekeeping chief Hervé Ladsous told the 15-nation Security Council that armed forces of each country had yet to leave. Ladsous said Sudan's Armed Forces and the armed branch of South Sudan's ruling party remain in Abyei, making the situation there very tense.

Under the terms of the June 20th deal, Khartoum and Juba agreed to withdraw forces from Abyei and allow a contingent of Ethiopian troops to be the sole military presence.

Violence has also broken in recent months in Sudan's border states of Blue Nile and Southern Kordofan, where Sudanese soldiers are battling former rebels traditionally viewed as allies of South Sudan.