The UN Security Council was set to vote Thursday on a resolution demanding an end to the siege of El-Fasher in Sudan's Darfur region, where fighting between government and paramilitary forces has provoked a humanitarian crisis.

War has raged for more than a year between the regular military under army chief Abdel Fattah al-Burhan and the paramilitary Rapid Support Forces led by his former deputy Mohamed Hamdan Daglo.

El-Fasher in North Darfur is the only state capital in the vast western region not under RSF control, and was previously a key humanitarian hub for a region now on the brink of famine.

The Security Council resolution, prepared by Britain and seen by AFP, "demands that the Rapid Support Forces halt the siege of El Fasher."

It calls for "an immediate halt to the fighting" and "withdrawal of all fighters that threaten the safety and security of civilians."

Earlier in June, UN Secretary-General Antonio Guterres urged a ceasefire in the wake of a paramilitary attack on a village that reportedly left more than 100 people dead.

The UN committee that coordinates humanitarian aid, representing 19 different organizations, demanded access to Sudan in a joint statement last month, warning of a "nightmare scenario."

"A famine will take hold in large parts of the country. More people will flee to neighboring countries in search of sustenance and safety. More children will succumb to disease and malnutrition," the Inter-Agency Standing Committee said.

The UN Security Council already demanded a ceasefire in March to mark the Muslim holy month of Ramadan, but with no effect.