The Southern African economic bloc said it would appeal for US$2.7 billion (NZ$3.7 billion) from the international community to help more than 23 million people in "urgent need" because of a blistering drought.
Ian Khama, chairman of the Southern African Development Community (SADC), who is also president of Botswana, will "this month declare a regional disaster," SADC said in a statement released on Monday (local time).
Five member states, Lesotho, Malawi, Namibia, Swaziland and Zimbabwe, have declared national drought emergencies.
South Africa has declared a drought emergency in eight of the country's nine provinces, while Mozambique has declared a 90-day institutional red alert for some southern and central areas.
"The appeal will be a formal request to the international community to provide assistance to affected member states," the SADC said.
Southern Africa has been hard hit over the past year by an El Nino-inspired drought that has wilted crops, slowed economic growth and driven food prices higher.