address contacts between the trump campaign and russia or the question of collusion. it only dealt with the clinton e-mail investigation. as we were walking, i asked him about michael cohen, his longtime lawyer and fixer. sources telling abc news cohen is likely to cooperate with federal prosecutors. are you concerned michael cohen will flip on you? >> i have nothing to do with that. >> reporter: later, i pressed him again. >> i just want to know if you're worried if he's going to cooperate with federal investigators. >> no, i'm not worried because i did nothing wrong. >> reporter: the president holding court for nearly an hour, also celebrating his summit with kim jong-un. >> i did a great job. >> reporter: bragging he "solved" the problem of north korea, though there is no agreement on how and when kim will give up his nuclear weapons. and he made this jaw-dropping comment about the dictator. >> hey, he is the head of a country, and, i mean, he is the strong head. don't let anyone think anything different. he speaks, and his people sit up