A surge in oil prices and the fast recent drawdown in global stocks of cereals raise the specter of a return to a supply crisis, FAO Director General Jacques Diouf told Reuters in an interview during a visit to the United Arab Emirates.

"The high prices raise concern and we've been quickly drawing down stocks," he said. "For years we have warned that what is needed is more productivity and investment in agriculture."

The most recent UN Food Price Index showed prices have risen to the highest levels since at least 1990, when the index began.