Three UN agencies warned Thursday of a "significant deterioration" in the nutrition situation of children and mothers in war-torn Sudan, calling for "urgent action".

"The lives of Sudan's children are at stake and urgent action is needed to protect an entire generation from malnutrition, disease and death," the United Nations children's agency (UNICEF), the World Health Organization (WHO) and World Food Program (WFP) said in a statement.

Sudan has been in the throes of conflict for over a year between the regular army led by de facto ruler Abdel Fattah al-Burhan and the RSF led by his former deputy, Mohamed Hamdan Daglo.

The conflict has killed tens of thousands of people, including up to 15,000 in a single West Darfur town, according to UN experts.

Nearly nine million people have been forced from their homes.

"The ongoing hostilities are worsening the drivers of child malnutrition," the agencies said.

"These include a lack of access to nutritious food, safe drinking water and sanitation, and increased risk of disease," they added.

"Sudan is facing an ever-increasing risk of conflict-induced famine that will have catastrophic consequences including the loss of life, especially among young children."

The agencies said the conflict "is also severely impacting the delivery of humanitarian supplies, leaving countless women and children without access to vital food and nutritional support... (while) growing violence and bureaucratic procedures impede access to conflict affected areas".

Child malnutrition in Sudan is "at emergency levels", the statement said.

In Central Darfur, acute malnutrition is estimated to be at 15.6 percent among children under five, while at the Zamzam camp for displaced people in North Darfur state it is close to 30 percent.

"We need immediate and safe access to deliver the humanitarian assistance that they so desperately need," said WFP head Cindy McCain.

"Millions of lives are at stake and the international community must act now or we risk losing an entire generation of children," she said.

The agencies warned: "The window to avert the worst is rapidly closing."