Sure he did....but it was through Paul, Barnabas, Timothy, Mark, Luke and others, not of the original twelve....that this commission was given.
Jesus had a little involvement with Gentiles: John 12:20 states that there was a party of Greeks that came to see Him ride into Jerusalem, and also John 4 which tells of the conversion of the Samaritans, but, sure, he mostly left his fledgling Church to go out to the Gentiles.