Sudan's Omar Bashir warns about disputed Abyei region
Sudan President Omar al-Bashir has said the disputed border region of Abyei is a source of potential conflict with newly independent South Sudan.
Abyei remains part of Sudan and the protocols governing it must be respected, Mr Bashir told the BBC a day after South Sudan's independence.
He spoke of his sadness over the division of his country, but said it was a price worth paying for peace.
The south struggled to break away for decades at a cost of 1.5 million lives.
In the latest event to mark the new nation's independence, South Sudan played its first football match, in the capital, Juba.
However, the new national team lost 3-1 to Kenyan club side Tusker FC after taking a 1-0 lead.
South Sudan has not yet been accepted as a member of the world football body Fifa and so the match was not officially recorded.
President Bashir said he would have preferred to preserve the unity of Sudan, in an interview for the BBC's Hardtalk programme on the day after South Sudan gained independence.
But the will of the people in the south had to be respected to avoid a return to armed conflict, he conceded.
Asked about potential sources of friction in the future, Mr Bashir pointed to Abyei, a border area claimed by both north and south.
Fighting in Abyei and another border region, South Kordofan, forced some 170,000 people to flee their homes in the run-up to southern independence.
Both sides agreed to withdraw their troops, leaving a 20km (12-mile) buffer zone along the border, in a deal brokered last month.
The BBC's Peter Martell in the southern capital, Juba, says the agreement is not easy to implement, because parts of the border are still contested and have not been demarcated.
In a clear warning to the south, Mr Bashir said there could be renewed hostilities if agreements on disputed areas such as Abyei were not respected.'Ethiopian troops welcome'
He said Abyei was a part of Sudan and could only join the south with the approval of nomadic Arab tribes in a future referendum, which he described as an unlikely scenario.
He said he wanted United Nations peacekeepers currently patrolling the region to leave.
But he welcomed the prospect of their replacement by Ethiopian troops, a move endorsed by the UN Security Council earlier this week.
"The Ethiopians have a mandate to keep peace in the zone, so we welcome the Ethiopian troops. Both of us welcome them, because they are capable of doing their job, unlike the current troops who have failed to keep peace in this zone," the president said.
"There are some arrangements, and as of now we are talking about creating some institutions. Two presidential representatives from each side. These are the authorities which will be running Abyei, security-wise and service-wise."
"There's a protocol on Abyei - a protocol that governs Abyei if there's a peaceful solution. But in the past, we were forced to fight when they [the south] tried to impose a new reality."
Both Sudan and the South are reliant on their oil revenues, which account for 98% of South Sudan's budget. But the two countries cannot agree how to divide the oil wealth of the former united state. Some 75% of the oil lies in the South but all the pipelines run north. It is feared that disputes over oil could lead the two neighbours to return to war.
Although they were united for many years, the two Sudans were always very different. The great divide is visible even from space, as this Nasa satellite image shows. The northern states are a blanket of desert, broken only by the fertile Nile corridor. South Sudan is covered by green swathes of grassland, swamps and tropical forest.
Sudan's arid north is mainly home to Arabic-speaking Muslims. But in South Sudan there is no dominant culture. The Dinkas and the Nuers are the largest of more than 200 ethnic groups, each with its own languages and traditional beliefs, alongside Christianity and Islam.
The health inequalities in Sudan are illustrated by infant mortality rates. In South Sudan, one in 10 children die before their first birthday. Whereas in the more developed northern states, such as Gezira and White Nile, half of those children would be expected to survive.
The gulf in water resources between north and south is stark. In Khartoum, River Nile, and Gezira states, two-thirds of people have access to piped drinking water and pit latrines. In the south, boreholes and unprotected wells are the main drinking sources. More than 80% of southerners have no toilet facilities whatsoever.
Throughout the two Sudans, access to primary school education is strongly linked to household earnings. In the poorest parts of the south, less than 1% of children finish primary school. Whereas in the wealthier north, up to 50% of children complete primary level education.
Conflict and poverty are the main causes of food insecurity in both countries. In Sudan, many of the residents of war-affected Darfur and the border states of Blue Nile and South Kordofan, depend on food aid. The UN said about 2.8m people in South Sudan would require food aid in 2013. The northern states tend to be wealthier, more urbanised and less reliant on agriculture.