Africa stands poised to “turn the corner once and for all” on building food and nutrition security and helping lift itself out of poverty, Kofi Annan, the former secretary-general of the United Nations, said.

But the continent still faces many challenges in launching its own “Uniquely African Green Revolution” and becoming able to grow enough food to feed itself, Annan said during his keynote address to the World Food Prize Borlaug Dialogue in Des Moines, Iowa, Thursday.

Annan, who currently serves as chairman of the Alliance for a Green Revolution in Africa or AGRA, said no one should underestimate the depth of the problems confronting Africa’s millions of small farmers, many of whom barely operate above a subsistence level and are dealing with growing pressures on their land.

“There is a huge amount more to do. Many millions are still going hungry. Populations continue to grow, and climate change is, almost by the day, adding to the pressures on Africa’s land,” Annan said. “But I remain very optimistic about Africa’s chances to turn the corner once and for all.”