A U.N. agency says an increase in the cost of grain and sugar helped to drive up global food prices in July, as a widespread U.S. drought continues punishing corn crops.

The Food and Agriculture Organization's Food Price Index that measures the monthly change in the international prices of a basket of food commodities climbed 6 percent in July.

The index averaged 213 points, up 12 points from the previous month and still well below the peak of 238 points in February of last year.

The FAO is tasked with reducing world hunger at a time of near-record high food prices.

The agency says the severe drought-related deterioration of U.S. corn yield prospects pushed that grain's prices up by nearly 23 percent in July.