Southern President Salva Kiir held two days of talks with Sudan's President Omar Hassan al-Bashir to ease tensions that have grown since South Sudan became independent in July as part of a peace agreement in 2005.
A diplomat said the talks were a positive sign that both sides wanted to improve ties but more time was needed to sort out their complicated disputes.
At a joint news conference both leaders said more negotiations would be held. "My government is ready to discuss solutions for all pending issues," Kiir said before leaving Khartoum. "I return today to Juba to ensure that we reach solutions to all pending issues. Lets sign an agreement as soon as possible."
Bashir said committees would work out solutions for all disputes in a set timeframe. He did not elaborate.
The African Union and former South African President Thabo Mbeki have tried to mediate but little has been resolved. A lack of a joint banking system and trade agreements is hampering cross-border commerce between north and south.
The United States has urged both sides to speed up talks to reach especially a deal on how to divide oil revenues -- the dominant source of revenue for both states. Juba took most of the oil but need to pay a fee to use northern export facilities both sides have failed to agree upon.