Sudan will treat South Sudanese as foreigners from April, state media said Thursday, adding to uncertainty over the fate of 700,000 southerners living in the north six months after independence.

South Sudan became Africa's newest nation in July after a 2005 peace agreement that ended decades of civil war of the mainly Muslim north and the South where most follow Christian and traditional beliefs.

More than 350,000 southerners have gone home since October 2010 after living in the north for decades but some 700,000 southerners still live in the north, according to the United Nations.

Sudan's cabinet said it would treat southerners as foreigners from April 8, state news agency SUNA said. They would have to get residency or work permits after that, officials have said.

The United Nations has warned southerners will face legal uncertainties in the north because Juba has not yet opened an embassy that can issue passports.

Not all southerners will have left by April. Many say they want to go home but others hope to stay since they have jobs and fear unemployment in the poverty-stricken south.

(Reporting by Ulf Laessing)