WASHINGTON, D.C. --- The U.S. Environmental Protection Agency last week said it will not curtail a rule requiring that ethanol be added to gasoline, CNNMoney.com reported. The EPA rejected a claim that the rule was artificially raising food prices.

Texas Gov. Rick Perry in April petitioned the EPA to grant a 50 percent waiver on the nation's Renewable Fuel Standard. The standard calls for 9 billion gallons of corn-based ethanol to be added to gasoline supplies in 2008.

"I am greatly disappointed with the EPA's inability to look past the good intentions of this policy to see the significant harm it is doing to farmers, ranchers and American households," Perry said in a released statement. "For the EPA to assert that this federal mandate is not affecting food prices not only goes against common sense, but every American's grocery bill."

EPA Administrator Stephen Johnson said Perry's waiver request was rejected because the agency did not find that the Renewable Fuel Standard caused "severe economic harm." Rather, Johnson said, the standard is "strengthening the nation's energy security and farm communities."