The Kenyan mediator of peace talks between the Sudanese government and the country's main rebel group says the two sides have made progress, but have yet to sign a peace deal.
The mediator, retired General Lazaro Sumbeiywo, says certain understandings have emerged in negotiations between the Sudanese government and the Sudan People's Liberation Army.
"This is purely on security arrangements," he said. "So far, I don't want to say which way. Until they sign, let me not commit myself."
One of the major sticking points concerning security arrangements has been the issue of the national army. The rebels were calling for two armies during an interim period - one in the north and one in the south - while the Sudanese government says government soldiers and the rebel forces should be merged into one army.
Mr. Sumbeiywo says the parties resolved that issue, but would not give details.
Remaining on the agenda are negotiations on how the two sides will distribute leadership and civil service positions, and share the country's wealth, which comes largely from the south's rich oil fields.
Mr. Sumbeiywo says negotiations will continue into Friday night, and he hopes the two sides will iron out their differences.
"I'm hoping that they will be able to resolve those outstanding issues that they have not had an understanding and then we can have an agreement on that segment," said Lazaro Sumbeiywo.
He says the two sides are close to reaching a peace agreement and are under tremendous pressure to do so.
"They're under pressure from everybody to have an agreement," he said. "The U.S., the European Union were here, their own constituencies, you know - they're under pressure from all over."
A source close to the talks told VOA there are still some outstanding issues in the area of security arrangements, and that all other issues can be solved if the two sides can work out that key issue. The source also says donors were on hand to discuss how they would fund and build infrastructure in Sudan during an interim period after a peace accord is signed.
Two weeks ago, first vice president Ali Osman Taha and rebel leader John Garang began face-to-face negotiations over how to save the faltering peace process.
Negotiations have been going on in Kenya for the past year to end the 20-year-old civil war, which has killed an estimated two million people.