Global crisis threatens to undo all UN's work: Ban

"It threatens to undermine all our achievements and all our progress," Ban told a meeting of U.N. agency chiefs devoted to the crisis. "Our progress in eradicating poverty and disease. Our efforts to fight climate change and promote development. To ensure that people have enough to eat."

At a meeting also attended by the heads of the World Bank and International Monetary Fund, Ban said the credit crunch that has stunned markets worldwide compounded the food crisis, the energy crisis and Africa's development crisis.

"It could be the final blow that many of the poorest of the world's poor simply cannot survive," he added, in one of his bleakest assessments of the impact of the financial turmoil.