The head of the World Bank is warning that global leaders must defuse currency tensions before they get worse, to avoid repeating the mistakes of the Great Depression.
Robert Zoellick was speaking ahead of this weekend's crucial meeting of his organisation and the International Monetary Fund.
Analysts say international tensions over currency levels pose a threat to the fragile economic recovery.
They have warned that conflict between China and the United States over the value of Chinese currency could cause more serious economic problems.