The United Nations estimates that more than $3 billion is needed for humanitarian aid and refugees in Sudan, where the humanitarian crisis has been further exacerbated by heavy fighting since mid-April.
For humanitarian aid alone, the UN says it needs $2.6 billion, according to its revised estimates, up from $1.75 billion in December.
These funds should enable humanitarian aid agencies to treat some 18 million of the most vulnerable people in the country, according to Ramesh Rajasingham, head of humanitarian affairs at the UN.
For refugees who have fled the fighting, the UN is asking for $470.4 million, adding that it expected to see up to 1.1 million people leave Sudan this year.
"Today, 25 million people -- more than half of Sudan's population -- need humanitarian assistance and protection," Rajasingham told reporters.
Fighting between General Abdel Fattah al-Burhane's army and General Mohamed Hamdane Daglo's Rapid Support Forces (RSF) paramilitaries, which began on April 15, has left an estimated 1,000 people dead and 1 million displaced and refugees in Sudan.
The fighting has worsened the humanitarian situation in the country, where one in three people were already dependent on humanitarian aid before the war.
Two weeks ago, the head of the UN High Commissioner for Refugees (UNHCR), Filippo Grandi, estimated that "more than 800,000 people" could flee the deadly fighting in Sudan.
"To date, the crisis, which began a month ago, has caused a mass exodus to neighboring countries of about 220,000 refugees," UNHCR official Raouf Mazou told reporters.
At the same time, more than 700,000 people have been internally displaced in Sudan. "Countless people remain trapped in Sudan, innocent victims of the indiscriminate fighting," he added.