South Sudan's Salva Kiir sacks bank chief Elijah Malok
South Sudan's President Salva Kiir has sacked the central bank governor - about a month after the new country launched its currency, the pound.
The dismissal of the governor, Elijah Malok, comes as the new currency has been sliding against the US dollar.
Mr Kiir said Mr Malok would be replaced by his deputy, Kornelio Koryom Mayiik.
South Sudan, which seceded from the north on 9 July, is battling to create a new state, analysts say.
Shortly after its independence, it accused the north of triggering an economic war by launching a new currency of its own.
The north also blocked an oil shipment from South Sudan, accusing it of failing to pay custom fees.
'Rise in inflation'
Mr Kiir dismissed Mr Malok by presidential decree and gave no reason for his decision.
Mr Mayiik, the new governor, had been in charge of a committee that oversaw the launch of the South's currency about a week after its independence.
The BBC's James Copnall in Sudan's capital, Khartoum, says the South is going through the complicated process of creating a modern state, while also dealing with major security and development challenges.
Mr Kiir was to have named a cabinet last week, but has so far failed to do so, our correspondent says.
Mr Kiir has insisted his choices will be based on quality, but he will find it difficult to escape ethnic considerations, he adds.
Economists are also worried about the lack of co-operation between Sudan and South Sudan.
Both states are locked in a race to replace their old currencies, raising fears of a sharp rise in inflation, our correspondent says.
The new currencies of both the north and the South are falling against the US dollar, he adds.
South Sudan has been selling US dollars to try to stop the slide in its currency, Reuters news agency reports.
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.