Fears have been heightened over soaring crop prices after the US reassessed grain harvests, slashing estimates for both corn and soybeans.
After a searing summer drought, a government estimate has cut corn production to the lowest level in six years and soybeans to the lowest in nine years.
The crucial Russian crop was also hit and now estimated at 9% lower than the August estimate - the second large cut in a row.
Neighbouring Kazakhstan's crop estimate has also been chopped by the US Department of Agriculture (USDA) by 4.5%.
Unfavourable weather conditions have increased pressure on prices for crops used for human consumption and livestock food chains.
A growing demand for biofuel has also prompted France to announce a decision that it would reconsider plans to further develop the use of alternatives to fossil fuels.
Once seen as a potential source of cheap alternative energy, biofuel is now blamed as a factor in soaring food prices.
French agriculture minister Stephane Le Foll said that the issue of "large quantities of agricultural products being diverted from food use should be put up for discussion".
And US livestock producers have petitioned the Obama administration for relief from a requirement to use corn-based ethanol in petrol.
Leaders of the G20 wealthy nations said the US grain forecasts would help determine if an emergency meeting is needed to constrain price upsurges.
France has suggested the creation of strategic stocks to buffer food price gyrations, days after agencies of the United Nations flagged a warning.
More than four years ago there were widespread food riots in a number of less developed nations because of sharp price rises.
World soybean prices have already risen by around 20% since 2011 and the USDA has now cut its forecast of the soybean crop by 2% from its August figure, twice the cut expected by traders.
The carry-over stockpile estimate at the end of the 2012 marketing year would be the smallest in eight years although slightly larger than expected.
Soybeans are used widely in advanced economies in pre-prepared meals.
Amid the concern, officials have offered some glimmers of hope with upwardly revised estimates, and expectations that the global rice harvest would not be affected.
With the US autumn harvest running faster than usual, the USDA lowered its corn forecast by less than 1% - traders had expected a cut of nearly 4% - from August.
The surplus at the end of this marketing year would be the smallest since 1996 but 24% larger than the trade expectation.
