Arbitration deal on Sudan's oil
Abyei has seen clashes recently which left much of its main town in ashes
Northern and southern Sudan have agreed to abide by international arbitration on the status of an oil-producing region both sides want to control.
Agreement was reached in Washington at talks mediated by US President Barack Obama's envoy to Sudan, Scott Gration.
Both sides said they would accept a ruling due next month from the Court of Arbitration in The Hague.
The dispute, over the region of Abyei, threatens a peace deal signed four years ago to end a 22-year civil war.
At stake is control of a large part of the country's oil wealth.
'Time is urgent'
Both the north and former rebels from the south want the oil fields around Abyei to be part of their own territories, and they cannot agree on the boundary for the area.
Last year, there were clashes in the town forcing some 50,000 people to flee their homes at the time.
Officials from South's Sudan People's Liberation Movement and President Omar al-Bashir's National Congress Party were joined by representatives from 20 countries in the US capital on Tuesday for talks aimed at keeping the Comprehensive Peace Agreement on track.
Mr Gration told delegates time was running out for finding a solution to Sudan's problems.
"Time is urgent," he said. "It's time to move forward. It's time to work together to bring peace to this country that's permanent and lasting."
The BBC's Richard Lister in Washington says there is a feeling in the international community that unless it bolsters the peace deal it is at risk of falling apart.
He says Mr Gration accepted that sounds of agreement made in the US capital may not necessarily be reflected later on the ground back in Sudan.
US officials say both sides have agreed to send their own officials to meet Mr Gration in Abyei when The Hague makes its ruling in July.
It is hoped Mr Gration's presence will be able to stifle anger from any dissenters that could trigger a return to widespread violence, our correspondent says.
Relations between the former foes in Sudan remain tense, with national elections due in 2010 and a referendum on whether the south should secede set for 2011.
The long civil war - separate from the Darfur conflict -between the mainly Muslim north and the Christian and animist south ended in 2005, after claiming 1.5 million lives.