$1.5 bn pledged by UN to curb Sudan's slide into 'death and destruction'

Donors at a UN conference on Monday pledged close to $1.5 billion to combat the humanitarian crisis in Sudan and help its neighbours host refugees fleeing the fighting.

Sudan is descending into death and destruction at unprecedented speed, UN chief Antonio Guterres warned as he urged donors to step in and curb the unfolding catastrophe.

The conference comes midway through a three-day ceasefire which appeared to have brought calm to the capital Khartoum, after the failure of earlier truces to secure aid corridors.

"Today, donors have announced close to $1.5 billion for the humanitarian response to Sudan and the region," the UN's humanitarian chief Martin Griffiths said, closing the conference hosted in Geneva.

"This crisis will require sustained financial support and I hope we can all keep Sudan at the top of our priorities."

UN refugees chief Filippo Grandi added: "It is very important these contributions be clearly allocated and disbursed as quickly as possible because we're really short of funds."

More than two months into the fighting, the United Nations is worried the crisis could spill over and destabilise neighbouring African states.

"The scale and speed of Sudan's descent into death and destruction is unprecedented," UN Secretary General Guterres told the conference.

"Without strong international support, Sudan could quickly become a locus of lawlessness, radiating insecurity across the region."

Since April 15, the army, led by Abdel Fattah al-Burhan, has been battling the paramilitary Rapid Support Forces (RSF) commanded by his former deputy Mohamed Hamdan Daglo, after the two fell out in a power struggle.

The death toll has topped 2,000, the Armed Conflict Location and Event Data Project said.

Hundreds of kilometres west of Khartoum, up to 1,100 have been killed in the West Darfur state capital El Geneina alone, according to the US State Department, blaming "primarily" the RSF.

A record 25 million people -- more than half of Sudan's population -- need aid, the UN says.

Roughly 2.5 million people have been uprooted across Sudan by the war, which has seen 550,000 seek refuge in neighbouring countries, according to UN figures.

While Griffiths highlighted donors' generosity, the amount pledged Monday was less than half of what humanitarians have said is needed this year to respond to the needs.

The UN has two appeals for tackling the crisis -- the humanitarian response within Sudan, which needs $2.6 billion this year, and the regional refugee response set at $470 million.

Both were less than 17 percent funded going into Monday's conference.

Qatar's prime minister told the conference there was "no military solution" to the conflict, as he pledged $50 million.

Sheikh Mohammed bin Abdulrahman bin Jassim Al-Thani urged the warring parties to "put the aspirations of the Sudanese people in the forefront".

The United States pledged the most at $550 million, followed by Germany with $162 million and the European Commission on $151 million, according to the UN.