ADDIS ABABA/KHARTOUM (Reuters) - Sudan and South Sudan on Monday began their first direct high-level talks on border security since a series of frontier clashes threatened to drag the former civil war foes back into a full-scale conflict.
Perched atop some of Africa's most significant crude reserves, the two countries have been mired in disputes over oil revenues and demarcation of their new border since South Sudan gained independence in July.
The African Union-mediated talks were cut short after South Sudan seized the Heglig oil field in a disputed border region in April, only to withdraw later under heavy international pressure.
The two returned to peace talks last week, after the United Nations threatened to impose sanctions if they failed to stop fighting and hammer out a deal.
"We are here for the joint political and security mechanism meetings - the body ... that is primarily drawing up the safe and demilitarized border zone," South Sudan's Foreign Minister Nhial Deng told Reuters ahead of the talks in the Ethiopian capital.
"We are always optimistic, you have to because it is optimism that fuels hope and hope helps you achieve success."
The two countries' defense and interior affairs ministers were also attending the negotiations, as well as military figures, officials said.
The talks have already been overshadowed by South Sudan's accusations of repeated air strikes by Khartoum. Juba announced on Friday it had filed a complaint at the U.N. Security Council.
Khartoum regularly denies accusations it is bombing South Sudan's border states, some of which are oil-producing. Such accusations are hard to verify as the remote area is difficult to access.
South Sudan has criticized Sudan for insisting on discussions on security ahead of other issues, in defiance of the U.N. peace plan.
Sudanese officials denied making preconditions.
"The meetings will kick-start this afternoon and we are hopeful these issues will be addressed in a very genuine and action oriented way," said Omer Dahab, spokesman of Khartoum's delegation.
Sudan paved the way for the resumption of talks on Friday after it announced the withdrawal of its security forces from the disputed Abyei region, as demanded by the United Nations.
Abyei, seized by northern troops last year, is a major bone of contention between the two countries. It has fertile grazing land and some oil reserves.
In Khartoum, the head of the Sudanese side of the joint Abyei administration accused members of the southern Dinka tribe, which is allied to Juba, of trying to cause chaos in the region after army's withdrawal.
"There were some provocations and property of citizens was looted," Khair al-Fahim, told reporters in the Sudanese capital Khartoum.
"We call on the U.N. peacekeepers to stop these provocations," said Fahim who belongs to the Arab Misseriya tribe, which is allied to Khartoum.
South Sudanese overwhelmingly voted to secede from Sudan in a referendum last year, promised in a 2005 peace deal that ended decades of north-south civil war.
The new, landlocked South inherited most of the old united Sudan's known oil reserves. But it shut down production in January to stop Khartoum taking oil for what the latter called unpaid export fees.
Additional reporting by Ulf Laessing; Writing by Aaron Massho and Alexander Dziadosz; Editing by Alison Williams