South Sudan and Sudan have failed to reach an agreement on security arrangements and oil exports, officials said Saturday after several days of talks in Ethiopia's capital.

The two sides were in Addis Ababa negotiating the implementation of a safe demilitarized border zone, which called on both Juba and Khartoum to withdraw their armies at least 6 miles (10 kilometres) from the contested border region.

South Sudan broke away from Sudan in 2011 after an independence vote under a 2005 peace treaty that ended decades of war but disputes remain over their common border and sharing of oil revenues.

A key sticking point has been the demilitarization of a contested 14-mile (23-kilometre)strip of land bordering Sudan's Darfur and South Sudan's Northern Bahr el Ghazal states.

"Each government has its own understanding of the scope of the 14-mile area," South Sudan's negotiating team said in a statement, which goes on to call Sudan's position "intractable."

Earlier this week, South Sudan's negotiating team claimed South Sudan had taken a step toward implementing the border security agreements by withdrawing its own forces from the disputed border.

However South Sudan's Military spokesman Col. Philip Aguer said no such withdrawal has taken place.

"(As of) Yesterday (Friday) evening there was no order withdrawal that we have received from any source," said Aguer. "The negotiation is at the political level. We are at the operation level. So far nothing has reached the SPLA general headquarters."

The demilitarized border is the first in a series of issues that may eventually have led to the resumption of South Sudan's oil production and export through pipelines in Sudan. Juba shut down its production last January after accusing Sudan of stealing its oil before it reached export facilities in Port Sudan, on the Red Sea. The shutdown eventually led to open clashes between the two countries' armies and condemnation from the international community.

In September, the two sides signed an agreement on border security and oil production that was expected to end their disputes. But subsequent negotiations have shown both sides are unable to implement the agreements they previously signed. The latest round of talks started on Jan. 14.

According to the statement from the South Sudan negotiating team, Sudan has refused to export southern oil until the border security arrangements are fully implemented. This includes the deployment of more than 800 Ethiopian security forces along the border to monitor the agreement.

Sudan has also frequently accused South Sudan of supporting rebels in Sudan's South Kordofan and Blue Nile states. The rebel groups were part of South Sudan's army during its 21-year civil war with Khartoum. But since the South's independence it maintains it has cut off support for the rebel groups. Khartoum has insisted Juba must stop supporting the rebels before border security arrangements can be implemented. South Sudan however says Khartoum is trying to delay the negotiations by "imposing new conditions" not in previous agreements.

It is unclear when the two sides might meet again to break the nearly four months of deadlock. But according to South Sudan's negotiating team, any chance of implementing the September agreement "will require greater co-operation from Sudan."