The Sudanese government is seeking $2.6bn from donors to help rebuild its southern region after a 21-year civil war.
So far, the rebuilding process has been overshadowed by violence and allegations of war crimes in western Darfur.
Opening the two-day conference in the Norwegian capital, Oslo, UN Secretary General Kofi Annan warned that peace accords around the world often collapse into fighting.
Mr Annan urged more aid to bolster the North-South peace deal that ended the conflict last January.
He told the 60-nation conference, 'over the past three decades, no fewer than half of all post-conflict situations have reverted back to war within five years of the signing of a peace agreement.'
A report by the United Nations and World Bank, backed by Egypt and the former rebel Sudan People's Liberation Movement (SPLM), says Sudan needs $2.6 billion in aid to help build the country’s infrastructure.
More than two million people were killed and four million displaced by a conflict complicated by issues of oil, ethnicity and ideology.
