Mediators in the talks between Sudan and South Sudan say their heads of state will meet soon, as the two sides continue talks on land demarcation and division of oil revenues

On Tuesday in Addis Ababa, representatives from both countries agreed to set up commissions to handle complex nationality and border issues that have heightened tension between the countries.

Sudanese President Omar al-Bashir and South Sudanese President Salva Kiir are expected to sign the pacts during a ceremony in coming weeks.

South Sudan split from Sudan in July, but key issues have remained unresolved, and progress at the 10-day talks in Addis Ababa has been slow.

A VOA correspondent at the talks reports one panel will try to settle the status of some 700,000 southerners in the north who became foreigners when the two Sudans separated.

There are also thousands of northerners living in South Sudan. They would have to be repatriated by April 8 unless a new deal is reached.

The other commission is to focus on the demarcation of areas that are not in dispute, including the lengthy process of preparing local residents for the property split.

Meanwhile, the African Union-mediated talks are expected to continue on the bitter dispute surrounding oil revenue sharing.

South Sudan took more than 70 percent of Sudan's oil after becoming independent. But the landlocked south relies on oil pipelines that run through the north to export its oil.

The two nations are at odds about fees for South Sudan's use of Sudan's oil pipelines and export facilities. The disagreement has led South Sudan to shut down its oil production in January.

The two Sudans' economies rely heavily on oil revenues.