UN experts on Thursday accused the two sides in Sudan's civil war of using "starvation tactics" against 25 million civilians, leaving 97 percent of the population facing " "severe levels of hunger".
"Never in modern history have so many people faced starvation and famine as in Sudan today," said the group of about a dozen independent experts.
"The world must pay attention to the largest modern famine taking shape in Sudan today," said the experts, who are appointed by the UN Human Rights Council, but do not speak on behalf of the United Nations.
War has raged since April 2023 between the Sudanese army under the country's de facto ruler Abdel Fattah al-Burhan and the paramilitary Rapid Support Forces, led by his former deputy Mohamed Hamdan Daglo.
Both sides have been accused of war crimes, including targeting civilians and blocking humanitarian aid.
The experts, including the special rapporteurs on the right to food and to safe drinking water and sanitation, demanded in a statement that both RSF and SAF "stop immediately obstructing aid delivery in Sudan".
"Both SAF and RSF, along with their foreign supporters, are responsible for what is an apparent deliberate use of starvation, constituting crimes against humanity and war crimes under international law," they said.
The conflict has left tens of thousands dead, and spurred more than 11 million people to flee their homes, including nearly three million now in other countries, according to the UN.
Some 26 million people face severe food insecurity, with famine declared in the Zamzam displacement camp in Sudan's western Darfur region.
The experts warned that other displacement camps in the region "are also at risk of famine".
Barely any aid has reached Zamzam or the surrounding area, and assistance has only trickled into the entire Darfur region since the army-aligned government reopened the Adre crossing with Chad this month.
In their statement, the experts said "the volume of aid currently being delivered through this corridor is not enough to meet the population's needs".
The onset of rainy season floods had worsened the suffering, they said, adding that "agricultural damage and livestock losses are significant, and mining and water contamination complicate the crisis".
The experts called for more international funding, pointing out that the $1.44 billion needed for the humanitarian response plan for Sudan this year was only halfway funded.