But he said such opportunity is limited, and he urged Haitians to take advantage of it.

Instability warnings

Clinton and Ban also met Rene Preval, the Haitian president, to discuss economic assistance to the country.

The visit comes amid warnings by aid agencies including the International Crisis Group that instability could return to Haiti if the government fails to secure international aid and improve management.

Haiti continues to suffer the effects of riots triggered by soaring food prices and four devastating storms last year.

But Clinton reminded a group of university students that Haiti was once "the richest island in all of the Caribbean ... because of the natural resources, because of what God had put into the land".

"It can be again, because of the resources in your mind and in your heart," he said.