"Do you think Iran would come to the U.S. if they had any place else they could buy it?" said Jerry Gidel, analyst for North America Risk Management Services. "In general, they need wheat. They're searching the world for wheat. They're buying the U.S. because it's the only thing they can buy."

Robert Looney, a professor of economics in the department of national security at the Naval Postgraduate School, said Iran appeared to be trying to diversify its food sources in response to rising commodities prices. "Politically they would have a hard time domestically unless they had some other reasons justifying it," he noted.