jorge sanchez, at the cuba u.s. for studies, says the u.s. is missing out at a lucrative opportunity to extract the oil. >> it requires big companies and great amounts of resource. so these when we have the opportunity with oil companies for the united states. >> reporter: it's an opportunity lost by the united states and an opportunity seized by canada, france and brazil. it's a different story for american farmers. big u.s. agricultural companies have won the right to ship their goods to cuba. >> translator: the united states is providing just basic food and their exports are already 50% of spanish expos. that's only food. so the potential for the united states is strong. >> reporter: ships hauling american farm products routinely visit havana harbor. about $700 million worth of food last year and growing. rafael hernandez, the editor of "pamas" magazine in havana says good business trumps ideology. >> i have a business. rice growers, republican guys, who are not liberal democrats. guys from louisiana, iowa, delaware, nebraska, minnesota. t