United crashed out of Europe's biggest club competition - one they have won three times - on Tuesday when they lost 3-2 in Wolfsburg.
Van Gaal's critics again railed against the Dutchman in the wake of the defeat
Paul Scholes labelled United "average" while his former team-mate Rio Ferdinand said dropping into the Europa League was "an embarrassment".
But Van Gaal launched an impassioned defence of his management at his weekly press conference.
When asked if he doubted his ability to win trophies with United, Van Gaal said: "No
I don't have any doubts."
The United manager admitted his players were struggling to deal with the expectations on their shoulders.
He said: "You can lose and you can win in sport, and you have to accept that, as a player and as a manager, but you have to work very hard and I am working very hard and my players are working very hard and doing everything we can do.
"The problem is that we have to meet the expectations and the expectations at a club like Manchester United are very high, and that's our problem."
Source : PA
Source: PA