The head of the International Monetary Fund warned Friday that soaring world food prices can have dire consequences, such as toppling governments and even triggering wars.

Dominique Strauss-Kahn told France's Europe-1 radio that the price hikes that set off rioting in Haiti, Egypt and elsewhere were an "extremely serious" problem.

"The planet must tackle it," he said.

The IMF chief said the problem could also threaten democracies, even in countries where governments have done all they could to help the local population. Asked whether the crisis could lead to wars, Strauss-Kahn responded that it was possible.

"When the tension goes above and beyond putting democracy into question, there are risks of war," he said. "History is full of wars that started because of this kind of problem."

Strauss-Kahn was appointed last year to head the IMF. He was a finance minister in the late 1990s in France.

Also on Friday, French President Nicolas Sarkozy suggested a global partnership among financial institutions, governments and the private sector to tackle the reasons for rising food prices. He also said France is doubling its food aid budget this year to $159 million US because 37 countries are experiencing "serious food crises."

Globally, food prices have risen 40 per cent since mid-2007. The increases hit poor people hardest, as food represents as much as 60-80 per cent of consumer spending in developing nations, compared with about 10-20 per cent in industrialized countries, the UN's Food and Agriculture Organization has said.