New Delhi ? Soaring world food prices may dip in coming months, but steadily rising demand means higher food costs are probably here to stay during the coming decade. That could fuel growing hunger and unrest in the world’s poorest and most vulnerable nations, a United Nations agency reported Thursday.

In one of the strongest statements yet of the potential scale and impact of the world food price crunch, the UN Food and Agriculture Organization said there is ample reason to believe that “permanent factors” and not just inclement weather are behind the current rise in prices and that those will keep food costs at “higher average levels than in the past.”

Compared with the past 10 years, wheat and corn prices are likely to be 40 percent to 60 percent higher, sugar prices 30 percent higher, and butter and oil prices 60 percent to 80 percent higher in current dollars over the coming decade, though the real increases could be somewhat less when inflation is taken into account, the organization said Thursday in its annual outlook report on world agriculture.