Governments must act to prevent a global food crisis that may "hit us very soon," said Shenggen Fan, director-general of the International Food Policy Research Institute.

The United Nations (UN) Food and Agriculture Organization (FAO) has called on the United States to suspend the mandate that results in 40% of the corn going to make biofuel. Suspension of the quota would allow more of the crop to go for food production.

"With world prices of cereals rising, the competition between the food, feed and fuel sectors for crops such as maize, sugar and oilseeds is likely to intensify. One way to alleviate some of the tension would be to lower or temporarily suspend the mandates on biofuels," stated Jose Graziano da Silva, director general of the UN FAO.

The US Renewable Fuels Standard, or RFS, has long been controversial, with many blaming the quota for pushing up corn prices. The RFS requires 13.2 billion gallons of ethanol to be made from corn in 2012.

The United Nations and Food Policy Research Institute are not alone in calling for the US quota to be suspended. Livestock producers in the US, worried about the cost of cattle feed, also want it scrapped and the governments of China, India and France have expressed concerns about the policy.