Final results from last month's referendum, released on Monday, showed that nearly 99 percent of the 3.9 million voters in south Sudan elected to separate form the Arab-led and Muslim north.

Despite fears that the vote, the centerpiece of a 2005 peace agreement which ended a decades-old civil war, could result in a widespread return to violence, observers say this has so far failed to materialise, although clashes in border regions last month left dozens dead.

"The worst case scenario didn't happen ... but the hardest part is still ahead of us," Peter Zangl, director general of the European Commission's humanitarian aid department said during a debate in the European Parliament on Tuesday.

A complete lack of development in southern Sudan for the past 25 years, security failings and a history of epidemics and floods are among the challenges facing the region, set to gain independence in July, said the official.

On top of this, an estimated two million migrants have moved from north to south Sudan as a result of the vote, with many unaccustomed to their new and tougher living conditions.

"The message to EU development commissioner Andris Piebalgs at the African Union summit in Addis-Ababa last month was that despite what's happening in northern Africa at the moment, Sudan is probably the continent's biggest challenge," said Mr Zangl.

"If Sudan was to return to conflict it would result in a major security risk for the whole region," he added.

Measured statements by Sudan's current president Omar al-Bashir have been welcomed by the international community, especially his acceptance of Monday's referendum results which will see the south break away from Khartoum's control.

Media reports quoting unnamed officials suggest Mr Bashir may be set to gain a one-year reprieve from war crimes charges, as Western governments seek to consolidate peace between north and south Sudan after last months referendum.

Mr Bashir is wanted by the International Criminal Court in the Hague for his role in the Darfur conflict.

European Parliament President Jerzy Buzek said during Tuesday's debate that the former Czechoslovakia offered a model for separation. In 1992, due to growing nationalist tensions, the central European state was peacefully dissolved by parliament and soon after was formally separated into two independent countries: the Czech Republic and Slovakia.

"We have strong hopes that it will be a friendly division," said the Polish politician. "The referendum was important because it sets an example for Africa. Sudan was a problem in the past and now can become a solution."

A number of outstanding issues could still derail the process, warn expects, among them the division of the country's oil reserves and establishing citizenship rights.