FILE - In this April 11, 2015, file photo, US President Barack Obama, right, smiles as he looks over towards Cuban President Raul Castro, left, during their meeting at the Summit of the Americas in Panama City, Panama. On Decmeber 17, 2014, Presidents Barack Obama and Raul Castro stunned the world by announcing an end to their nations’ half-century of official hostility. (AP Photo/Pablo Martinez Monsivais, File)