The secretary-general will co-chair a pledging conference in Addis Ababa, Ethiopia, on Thursday and then travel to Khartoum to meet Sudanese government officials, to the Darfur region for a first-hand glimpse of the conflict, and to Rumbek in southern Sudan to meet Sudanese rebel leader John Garang.
The secretary-general said there are plans to increase the African Union's force in Darfur from a little over 2,000 to 8,000, "and we are bringing together donors and partners who are in a position to help."
In addition to money, the African force needs help with logistics, communications, and transport, he said.
Annan will co-chair the pledging conference with African Union Commission Chairman Alpha Oumar Konare. NATO Secretary General Jaap de Hoop Scheffer and European Union foreign policy chief Javier Solana are also expected to attend.
During his Sudan trip, Annan said, he plans to meet U.N. staff, see the progress being made by African Union troops in Darfur, and assess the implementation of an agreement signed in January to end the 23-year civil war between the government and southern rebels. He returns to New York on June 1.