Kansas City, Mo. ? The United States needs to continue taking steps to protect its food supply from terrorism just as it would its buildings, airports and other elements of its infrastructure, FBI deputy director John S. Pistole said Monday.

Pistole, keynote speaker at the second International Symposium on Agroterrorism, told about 1,000 delegates from 21 countries attending the four-day symposium that terrorist groups like al-Qaida could threaten the food supply.

He said while there was no “specific communicated threat at this time,” the “absence of a communicated threat does not prove the absence of a threat.”

The U.S. food and agriculture industry employs about one in eight Americans and is important not only to Americans, but because of its massive exports, to much of the world, as well, Pistole said.

Barry Erlick, president of BJE Associates, said the U.S. food supply faces threats from livestock diseases around the world. He said there are several animal-borne diseases that occur in livestock overseas and have not been present in U.S. livestock. But he said terrorists could bring the diseases to the United States.