DES MOINES, Iowa (AP) — Governor Terry Branstad’s request for a federal disaster declaration to respond to the bird flu outbreak has been denied. The governor had sought a major disaster declaration from President Barack Obama for the four counties most impacted by the virus. In a letter from federal authorities dated Tuesday, the request was rejected.

The letter said the damage was “not of such severity and magnitude” that it could not be handled by the state. The virus has infected more than 31.5 million birds in Iowa, mostly egg-laying chickens, making the state the hardest hit in the nation. Branstad spokesman Jimmy Centers said the administration was gathering information to assess whether an appeal would be effective.