The presidents of Sudan and South Sudan have signed a series of deals on security and economic cooperation, though some major disputes that nearly pushed them into war remain unresolved.

Sudan's Omar al-Bashir and South Sudan's Salva Kiir took part in a signing ceremony in the Ethiopian capital, Addis Ababa, on Thursday.

The deals call for a demilitarized zone along the border and the resumption of southern oil exports through the north. Another deal calls for the creation of a so-called “soft border” which will allow people, trade and animals to flow “unhindered.”

The two countries remain divided over who controls the oil-producing Abyei region and other border areas. They signed a deal in which they agreed to continue working on border demarcation.

The north and south fought a 21-year civil war that eventually led to the south's independence in July 2011.

Lingering issues pushed the countries to the brink of war earlier this year. Sudan has accused the South of arming rebels in two of its states, while South Sudan accuses the north of launching air attacks.

South Sudan cut off oil exports through northern pipelines in January over a disagreement on transit fees. The lack of oil revenues has threatened the fragile economies of both nations.

The United Nations has threatened both countries with sanctions if they do not settle their issues.