Sudan's Abyei dispute: Bashir vows to remain
Sudan's president has said he will not withdraw troops from the disputed Abyei border region seized over the weekend.
President Omar al-Bashir said the area belonged to the north.
He added his army would respond to any possible "provocation" from the army of South Sudan, due to become an independent state on 9 July.
Northern troops seized the territory after southern forces had ambushed a convoy of its forces in the area, killing 22 people.
Analysts fear the the dispute could reignite the north-south conflict, in which some 1.5 million were killed.
The status of Abyei was left undecided in the 2005 peace deal and a referendum, due in January, on whether the area should be part of the north or south has been postponed indefinitely.
The two sides fought for decades before agreeing to share power and hold a referendum on southern independence.
"Abyei is northern Sudanese land," President Bashir said, according to Reuters, adding: "We will not withdraw from it."
Referring to US warnings that the seizure could jeopardise billions of dollars of possible debt relief and moves to drop sanctions, he said:
"Sudan is not greedy for the carrot of America, and does not fear from its stick."
On Tuesday, a southern minister in Sudan's national government resigned, saying "war crimes" had been committed in the region.
Luka Biong Deng, a senior official in the south's ruling party, originally from Abyei, said he could no longer work with Mr Bashir's party in the unity government.
Some 20,000 people have now fled the town of Abyei, which has been left deserted, aid workers say.
UN human rights chief Navi Pillay said she had received reports that northern forces had been shelling and bombing civilian areas.
The UN Security Council, which toured Sudan earlier this week, has urged northern forces to withdraw.
The US envoy to Sudan, Princeton Lyman, has warned that the takeover of Abyei put at risk moves to cancel billions of dollars worth of Sudan's debt.
He also said that Washington would find it difficult to remove Sudan from its list of state sponsors of terrorism unless troops were withdrawn from Abyei.
Under these sanctions Sudanese companies are banned from using US currency - a major obstacle to international trade.
The US has previously suggested that a peaceful transition to independence for the south and a negotiated solution to the separate conflict in Darfur could normalise relations.
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.