The leaders of north and south Sudan are set to meet in Ethiopia to discuss crucial unresolved issues as the south prepares to declare its independence on Saturday.

Sudanese President Omar al-Bashir and southern leader Salva Kiir are attending the talks Monday in Addis Ababa, as the two sides work to find solutions on resource sharing, disputed border areas and citizenship.

The meeting comes amid weeks of fighting in the volatile Southern Kordofan state and neighboring Abyei, which has led to a mass exodus of people and raised fears of a new Sudanese civil war.

Mr. Bashir has said he ordered his northern army to keep fighting in Southern Kordofan for as long as rebels are operating there.

Officials with southern Sudan's army said Sunday the fighting could spread into other border states, from Blue Nile to Darfur, unless a cease-fire is implemented.

North and south Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

Peacekeepers in Sudan's troubled Darfur region say an Ethiopian peacekeeper was shot dead.

The joint African Union – United Nations force said Saturday that attackers opened fire on a U.N. vehicle in the west Darfur city of El-Geneina on Thursday.

The mission says another peacekeeper was wounded in the attack.

It says the motive for the shooting is under investigation.

Rebels in Darfur took up arms against the government in 2003, accusing Khartoum of neglecting their region.

Fighting has continued for more than eight years with little progress in peace talks between Sudan's government and rebel groups.

The United Nations says more than 300,000 people have been killed in the Darfur conflict, and 2.7 million others have been displaced. Sudan's government puts the death toll at 10,000.

The U.S. envoy to Sudan is on his way to the country for talks aimed at ending hostilities between forces from northern and southern Sudan as the south prepares to declare independence next week.

A State Department statement Saturday says Princeton Lyman will attend South Sudan's independence ceremony on July 9 in the new capital, Juba.

The statement says Lyman heads first first to Addis Ababa, in nearby Ethiopia, where talks between northern and southern Sudan are ongoing as fighting rages in border areas, including Southern Kordofan and the oil-rich Abyei region.

The State Department says Lyman will support efforts in Addis Ababa to negotiate an end to the violence. Lyman will also attempt to broker agreements on unresolved issues including resource sharing, disputed border areas, and citizenship, all crucial to the future of the relationship between Sudan and South Sudan.

Lyman, the top U.S. diplomat for the region, is also scheduled to visit Khartoum, the capital of Sudan, to meet with officials there.

Friday, Lyman said the process of dividing Sudan into two independent states is “still fundamentally on track” despite the territorial and economic disputes. He said the political atmosphere surrounding the birth of the new state is not as promising as it seemed when the southern Sudanese voted to become independent six months ago, but he says he expects the north and south to be able to forge workable, if not cordial, relations.

But the same day, Sudanese President Omar al-Bashir said he had ordered his northern army to keep fighting in the volatile Southern Kordofan state for as long as rebels are operating there.

Weeks of fighting in Southern Kordofan and neighboring Abyei have led to a mass exodus of people and raised fears of a new Sudanese civil war.

North and South Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

Sudanese President Omar al-Bashir says fighting will continue along the country's north-south border until rebels in the region disarm.

In a speech Friday in Khartoum, Mr. Bashir said he has ordered his northern army to keep fighting in the volatile Southern Kordofan state for as long as rebels are operating there.

His comments come just days before South Sudan is set to officially separate from the north and declare independence on July 9. Despite the planned separation, fighting has raged on in Southern Kordofan and other border areas, including the oil-rich region of Abyei.

In another development Friday, the U.S. envoy to Sudan, Princeton Lyman, said Friday the process of dividing Sudan into two independent states is “still fundamentally on track” despite territorial and economic disputes.

Lyman says the political atmosphere surrounding the birth of the new state is by no means as promising as it seemed when the southern Sudanese voted to become independent in January.

But he says the political process is “still fundamentally on track” and that he expects the north and south to be able to forge workable, if not cordial, relations after July 9.

Weeks of fighting in Southern Kordofan and neighboring Abyei have led to a mass exodus of people and raised fears of a new Sudanese civil war.

North and South Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

Sudanese President Omar Bashir is rejecting calls to end the fighting along the country's north-south border.

Mr. Bashir said Friday his northern army would continue fighting armed groups in the volatile Southern Kordofan state.

South Sudan is set to officially separate from the north and declare independence July 9, but fighting has raged on in Southern Kordofan and other border areas, including the oil-rich region of Abyei.

The United Nations decries what officials have described as “utter devastation” along the border.

U.S. President Barack Obama last week called the situation in Southern Kordofan state “dire,” and the State Department has called for the violence to end so that humanitarian aid can get in.

Weeks of fighting in Southern Kordofan and neighboring Abyei have led to a mass exodus of people and raised fears of a new Sudanese civil war.

North and south Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

(Updates UN -SUDAN 6/30 new info graphs 4&5 )

The United Nation's humanitarian agency says Sudan is allowing it limited access to a volatile border town in the country's south but says many parts of the city are still off limits.

The United Nations Office for the Coordination of Humanitarian Affairs says its aid workers have been able to enter Kadugli, the capital of the tense Southern Kordofan state. However, the agency says the workers only have access to the parts of the city where aid groups have offices and says they are still not able to distribute aid to people in the city.

The United Nations said all agency offices in Kadugli have been looted.

On Thursday, U.S. State Department Spokesman Mark Toner said the U.S. Special Envoy to Sudan, Princeton Lyman,is planning to return to Ethiopia

in the coming days for African Union sponsored talks on Sudan.

Toner says all violence needs to end along Sudan's north-south border. He called on both sides to allow access for humanitarian aid.

Earlier this week, a senior U.N. human rights official said clashes along Sudan's north-south border have caused “utter devastation” in the region.

Weeks of fighting in Southern Kordofan and the neighboring Abyei region has led to a mass exodus of people and raised fears of a new Sudanese civil war.

Southern Sudan is set to declare independence on July 9, but northern and southern leaders have not agreed on their final border, nor on the future of oil-rich and fertile Abyei.

North and south Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

The United Nation's humanitarian agency says Sudan's government is allowing it limited access to a volatile border town in the country's south but says many parts of the city are still off limits.

The United Nations Office for the Coordination of Humanitarian Affairs says its aid workers have been able to enter Kadugli, the capital of the tense Southern Kordofan state. However, the agency says the workers only have access to the parts of the city where aid groups have offices and says they are still not able to distribute aid to people in the city.

The United Nations said all agency offices in Kadugli have been looted.

Earlier this week, a senior U.N. human rights official said clashes along Sudan's north-south border have caused “utter devastation” in the region.

Weeks of fighting in Southern Kordofan and the neighboring Abyei region has led to a mass exodus of people and raised fears of a new Sudanese civil war.

Southern Sudan is set to declare independence on July 9, but northern and southern leaders have not agreed on their final border, nor on the future of oil-rich and fertile Abyei.

North and South Sudan fought a 21-year civil war that ended with a 2005 peace deal. South Sudan voted to split from the north in a referendum in January.

The United Nations has criticized China for failing to arrest Sudanese President Omar al-Bashir during his visit to Beijing this week.

U.N. High Commissioner for Human Rights Navi Pillay said Thursday she is “disappointed” China welcomed Mr. Bashir, who is wanted by the International Criminal Court.

The ICC has charged Mr. Bashir with war crimes, crimes against humanity and genocide in Sudan's Darfur region.

Pillay said Thursday that even though China is not an ICC member, Beijing still has a responsibility to ensure the African leader is brought to trial.

China's foreign ministry said this week that it reserves judgement on the ICC's prosecution of Mr. Bashir.

The United Nations says fighting in Darfur has killed some 300,000 people and displaced 2.7 million since 2003.

President Bashir and Chinese President Hu Jintao signed loan and economic cooperation agreements in Beijing on Wednesday.

China is a key arms supplier to Sudan and its biggest purchaser of oil.

Southern Sudan, which will soon become an independent country, has asked the United States to lift oil sanctions on all of Sudan.

The south's vice president, Riek Machar, said Wednesday that the current sanctions will hurt the new country's ability to export oil because it must rely on the north's pipelines.

South Sudan is set to split from the north on July 9.

Machar spoke in Juba after arriving from the United States. He told reporters that the U.S. has promised to review the matter.

Most of Sudan's oil reserves are located in what will be south Sudan or in the disputed Abyei region.

Sudan is Africa's third-largest oil producer behind Nigeria and Angola.