The statement comes after considerable criticism in the African media of the failure of the continent’s leaders to help famine victims across the Horn of Africa.
The AU said the pledging conference would bring together heads of state and international donors.
The United Nations says the famine is spreading across southern Somalia.
The African Union statement was made by its deputy chairman, Erasmus Mwencha, during a visit to the AU peacekeeping mission in the Somali capital, Mogadishu.
“I ask the African continent, from the northern cape to the southern cape, to look hard at how they can contribute to alleviating the suffering,” said Mr Mwencha.
But he gave no date for the summit.
His call came as the United Nations warned that the crisis was intensifying, with more than 12 million people in Somalia, Kenya, Ethiopia and Djibouti urgently needing help.
The UN says that tens of thousands have already died and hundreds of thousands are at risk of starvation.