The move comes after two months of diplomatic wrangling over how to handle a separate crisis in Sudan's troubled western Darfur region, amid fears the ongoing violence there could derail the north-south agreement.

Addressing the council, the head of UN peacekeeping operations, Jean-Marie Guehenno, welcomed the move but warned "serious political hurdles" and "unprecedented logistical obstacles" still confront the peace process in Sudan.

The new peace mission was given a mandate to monitor the north-south ceasefire, help with demobilisation and disarmament, give assistance to elections preparations and other tasks.