Yambio - Sudan's president on Tuesday said he would support the country's oil-producing south if it chose independence in a looming referendum, in his closest acknowledgement of the possibility of separation.

The unusually conciliatory speech from President Omar Hassan al-Bashir came as Sudan marked the fifth anniversary of a 2005 peace deal that ended more than two decades of north-south civil war and promised the referendum.

Southerners are widely expected to choose independence in the ballot, scheduled for January 2011, although analysts have up to now warned Bashir's northern supporters would resist any loss of control over southern oil fields.

Bashir told dignitaries gathered in the remote southern town of Yambio that his northern National Congress Party (NCP) still wanted to keep Sudan unified.

Security was tight as Bashir spoke in a newly-constructed stadium in Yambio, close to the border with the Democratic Republic of Congo (DRC).

Analysts and activists have released a series of reports in recent weeks, warning Sudan's northern and southern armies were re-arming and the country could slide back to war in the run-up to the southern referendum.

South Sudan's President Salva Kiir, speaking at the same event, played down fears that the 2011 vote would lead to a confrontation with the north.