U.S. U.N. Ambassador Susan Rice said the demilitarized zone between the two countries is part of a road map devised by the U.N. Security Council and the AU, the Sudan Tribune reported. South Sudan has accepted the map.
"Its [Sudan's] refusal has prevented the establishment of a safe demilitarized border zone and the deployment of the joint border verification monitoring mechanism, and it risks the resumption of outright conflict," Rice said.
South Sudan won the right to secede and became independent last year. The two countries came close to war earlier this year in a dispute over the oil-producing province of Heglig.
Other issues at the peace talks are Sudan's allegations South Sudan is supporting rebel groups and the transit taxes South Sudan should pay for oil shipped across Sudan.