u.s. government for permission first. democratic congresswoman kathy castor, who just returned from a trip to cuba, wants to change that. >> i think it's time to try something different and end the embargo and lift these travel restrictions. >> reporter: it's estimated that thousands of americans travel to cuba every year, but an exact number is hard to come by. the treasury department which grants the licenses for travel to cuba still won't reveal exactly how many americans are going to the island. jim acosta, cnn, washington. just ahead tonight, more threats, more bluster from north korea's kim jong-un. also, a rare and very disturbing look at the lengths many north koreans have to go to to try to escape their homeland. oh, hi thehey!ill.