Here's a snip from an account of Costner's encounter with Castro, at a 2001 screening in Havana of the film "Thirteen Days", which Costner produced and had a supporting on-screen role in.
'Though Costner did not attribute a specific political agenda to his visit and claimed to be "unqualified" to make political judgments about Cuba, he was clearly moved by his encounter with the Cuban President. "It was an experience of a lifetime to sit only a few feet away from him and watch him relive an experience he lived as a very young man," Costner said at a press conference on April 11th at Havana´s elegant Hotel Nacional. "We all live in this world, and we all recognize Cuba is a big player although it is a small country," he said. "My interests aren't as political -- my life has been chosen to make films. I think humanity is a great experiment. Who is to say ... [that] the United States is right and Cuba is wrong?" '
-from World Press Review 5/7/2001
http://www.worldpress.org/Americas/478.cfm