South Sudan orders resumption of oil production
South Sudan has ordered oil companies to restart production immediately, ending its dispute with Sudan.
It halted production in January in a row with Sudan over oil transit fees. Tensions between the neighbours escalated to the brink of war.
A deal to resolve the issues was signed last month and ratified by the Sudanese parliament on Wednesday.
South Sudan's petroleum minister said it would be three months before oil reached international markets.
South Sudan seceded from Sudan in July 2011, taking two-thirds of the former Sudan's oil, but Khartoum retained the processing and export facilities.
Relations became strained, not just over oil but also over the exact location of their common border, which until now remains disputed.
The two countries' economies have been seriously damaged as a result of the stoppage - oil accounts for some 98% of South Sudan's revenue.
"The shutdown of oil production previously authorised by the Republic of South Sudan has served its purpose to protect the sovereignty and patrimony of the nation," AFP news agency quoted Stephen Dhieu Dau, the oil minister, as saying in a statement.
At the end of September, the leaders of Sudan and South Sudan agreed to resume oil sales - but few details were released about the deal mediated by the African Union.
They also agreed to set up a demilitarised buffer zone.
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.