last decade has been sergei kislyak. few the former russian ambassador now the former russian ambassador to the united states. u.s. intelligence also considered him one of russia s top spies and spy recruiters in washington. cnn spoke exclusively to kislyak about that and contacts with the trump campaign. fred pleitgen joins us live with the latest. matthew chance went a long way to get this interview, you had, fred? huh, fred? reporter: yeah, a 12-hour train ride to track sergei kislyak down. he s running as a politician there to get into russia s version of the senate. it was a testy exchange continue matthew and sergei kislyak. kislyak denying there were attempts to get together a back channel between the trump campaign and later the trump white house and russia. saying he doesn t recall whether any secret information was devolved in a meeting he had in the oval office with president trump.