The African Union says North and South Sudan have agreed on a framework to resolve most outstanding issues ahead of a vote on southern independence.

非洲联盟表示，南北苏丹已经同意在南苏丹独立投票之前解决大部分突出问题。

Registration¹ of voters for January's referendum is due to begin after a long delay" src="http://www.enread.com/upimg/allimg/101115/4_101115054233_1.jpg" width="304" height="171" />
Registration of voters for January's referendum is due to begin after a long delay

In a statement, the AU says both sides have agreed to demarcate（区别，标定） the north-south border while allowing northern nomads²（游牧民） to graze in the south.

The framework also includes commitments to allow Sudanese citizens the right to live in either North or South Sudan.

Meanwhile, voter registration for January's referendum（公民投票） is due to begin.

The referendum is part of a peace deal which ended a north-south civil war.

The BBC's James Copnall in Khartoum says the announcement from the AU's High Level Implementation³（实现，履行） Panel on Sudan will reduce some of the tension that has been growing in the build-up to the vote.

The statement said both parties "committed themselves to the immediate⁴ demarcation of the north-south border".

"In the event of secession, this will be the longest inter-state border in Africa, hosting in its immediate vicinity（紧邻） on both sides a significant proportion of Sudan's population," the statement said.

"The parties have committed themselves to maintaining a 'soft border', which will permit unhindered（不受妨碍的） economic and social activity and interaction, which will be essential for economic prosperity and harmony between the north and the south."

Under the new framework, the disputed border area of Abyei will be addressed directly by the presidents of Sudan and the semi-autonomous south, the statement says.

Logistical challenge

In another development, the much-delayed voter registration for the referendum is begins on Monday.

Registration is starting late, in part because of a number of political disagreements between north and south.

An estimated five million people are eligible⁵ to vote, and officials now have a shortened period of 17 days in which to register them.

Denis Kadima, director of the UN's Integrated Referendum and Electoral Division, said most of the materials should be in place, despite the huge logistical challenges, particularly in the South.

South Sudan, which has most of Sudan's oil reserves, is considered likely to vote for independence, but many southerners fear Khartoum will never let their region break away.