Delegates are gathering in Washington DC for the largest ever summit of African leaders in the US.
Nearly 50 heads of state are expected to attend the three-day event, which began on Monday. US Commerce Secretary Penny Pritzker has said about $900m (£535m) in business deals will be formally announced during the event.
But the presidents of Liberia, Guinea and Sierra Leone have cancelled their plans to attend amid an Ebola outbreak.
The disease has killed more than 800 people across West Africa.
US President Barack Obama promised to convene a summit during his three-country Africa tour last year, when he visited Senegal, Tanzania and South Africa.