Addis Ababa - Sudan and South Sudan are due to restart African Union-led talks in Ethiopia Tuesday in the first face-to-face meeting since bitter border fighting took the foes to the brink of all-out war.
International pressure has pushed both sides to return to the long-running talks stalled by the fighting last month, when Southern troops seized an oil field from Khartoum's troops for ten days as Sudan launched repeated air strikes.
Tensions remain high, but Southern President Salva Kiir stressed ahead of the talks that "amicable dialogue on the outstanding issues with Khartoum is the only option for peace," according the South Sudan government website.
Khartoum's foreign ministry has said it will attend the 29 May talks and discuss a UN Security Council resolution that they resume dialogue on "critical" issues unresolved after the South gained independence last year.
However, Khartoum on Sunday said it had complained to the UN Security Council over alleged "aggression" by the South, including alleged cross-border incursions, which it said broke a UN order to halt hostilities.
Juba has accused Khartoum of continued air strikes on its territory.
AU mediator and former South African president Thabo Mbeki has been shuttling between the two capitals in bid to ensure both sides attend the talks, which have already slipped from a UN Security Council 16 May deadline to start.
"The AU is doing its utmost at all levels to make the resumptions of these negations a success, because there is no other way than peace - war cannot solve the problem," AU spokesperson Noureddine Mezni told AFP.
Juba has said it is ready to comply with all articles in the UN resolution, while Khartoum committed itself to end hostilities but expressed reservations about some UN demands, which threatens sanctions for non-compliance.
Series of unresolved issues
It was not clear when exactly on Tuesday the talks are expected to start, or for how long the talks are due to last.
Mediators say the talks will focus on security issues, including ensuring both sides renew their commitment to earlier agreements to establish a demilitarised buffer zone scuttled by the weeks of fighting.
Troops remain dug in at positions along the contested frontier, and both sides accuse the other backing rebel forces to destabilise the other.
Mediators say that outstanding issues - including a bitter dispute over issues that include oil transit fees and contested border zones - are expected to be negotiated at later meetings.
"The coming days are crucial...this will pave the way for a successful negotiation, this will give us confidence," Mezni said.
South Sudan broke away from Sudan in July after a 2005 peace deal ended one of Africa's longest civil wars, which killed about two million people.
But tensions soon flared again over a series of unresolved issues, including the border, the future of disputed territories and oil.
The South separated with about 75% of the former united Sudan's oil production, but Juba still depends on the north's pipeline and Red Sea port to export its crude.
A protracted dispute over fees for use of that infrastructure led South Sudan in January to shut its oil production after accusing the north of theft.
The Security Council gave both sides three months to conclude the talks.