The former Chelsea boss says he is not interested in making slow progress improving a side who finished fifth in the league last season.
Instead he is aiming high by targeting the Premier League and satisfying the fans' hunger for watching an attacking brand of football.
Mourinho said: "I was never very good playing with words or hiding behind words or philosophies.
"In fact I never tried to be good, I was much more aggressive in my approach with the risks that can bring.
I want the fans to be behind us because we need them in the last ten minutes. Of course we are not going to get everything. But we want to."
Mourinho met the media for the first time at Old Trafford since being appointed as United boss on a three-year deal on May 27.
