The United Nations humanitarian response plan is seeking $2.56 billion to help people affected by the crisis in Sudan, a senior U.N. official said on Wednesday.

"Today, 25 million people, more than half the population of Sudan, need humanitarian aid and protection. This is the highest number we have ever seen in the country," said Ramesh Rajasingham, head of the U.N. Office for the Coordination of Humanitarian Affairs in Geneva and director of the Coordination Division.

"The funding requirements of nearly $2.6 billion is also the highest for any humanitarian appeal for Sudan." (Reporting by Gabrielle Tétrault-Farber; Editing by Andrew Heavens)