The Red Devils claimed a 4-0 win over Queens Park Rangers on Sunday to give Van Gaal his first victory in charge of the club.
"I want to win the Premier League title," BBC Sport quotes him as saying. "If it is not this year then the second or third year. I want to give a championship to the fans.
"My teams are always focused on attack, but it is not our focus, that is to be in the first three. The most important thing is the trajectory."
United are currently ninth in the Premier League table, with five points from four games.