Nuba refugees "exchange the peace" after a church service in the Yida refugee camp, South Sudan, April 2012.

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The talks are scheduled to take place in Addis Ababa, Ethiopia

On the agenda: security and border demarcation

South Sudan split from Sudan last year as part of a 2005 peace deal

CNN  — 

Peace talks between Sudan and South Sudan are scheduled to take place Tuesday in Addis Ababa, Ethiopia, the first such discussion since tensions peaked last month.

On the agenda, according to the United Nations, are security, the status of the countries’ citizens, border demarcation and the final status of the disputed oil-rich region of Abyei.

South Sudan split from Sudan last year as part of a 2005 peace deal that ended decades of war in Africa’s largest nation. The war left 2 million people dead and ended with the peace agreement that included an independence referendum for the south.

But clashes around oil-rich border areas have continued despite the split, sparking fears the two sides could return to an all-out war.

“They’ve agreed to withdraw from Abyei; well, do it! They’ve agreed to form a border monitoring mechanism. They’ve agreed actually on frameworks for addressing the border issues such as demarcation of those that they’ve agreed upon, and negotiating or founding a framework for that. Do it!” said the U.N. envoy for Sudan and South Sudan Haile Menkerios, according to the U.N. website, adding that he is hopeful about the talks.

Sudan’s official news agency, SUNA, reported that the Sudanese delegation is going into discussions with a “genuine desire to reach understandings.”

Tensions between the two nation peaked last month when South Sudan seized the oil-producing region of Heglig, which fuels the economies of both nations, from its northern neighbor. Heglig oil facilities account for about half of Sudan’s production of 115,000 barrels a day.

South Sudanese forces withdrew days later after Sudan lodged protests with the United Nations and African Union, but South Sudan said it continued to come under aerial and ground attack. Both countries have accused the other of supporting armed groups inside their territories, according to the United Nations.