Manchester United manager Louis van Gaal has admitted that his side's start to the Premier League season has not been good enough.

The Red Devils opened the new campaign with a 2-1 home defeat at the hands of Swansea City last weekend before being held to a 1-1 draw by Sunderland at the Stadium of Light this afternoon.

One point from the opening two games has seen some of the optimism surrounding Van Gaal's appointment fade away, and the Dutchman acknowledged that his side would need to improve.

"You can never say how long it takes because when you win the next match, the confidence comes back. But we have to work a lot," he told reporters.

"The players are very disappointed after the game because we thought we would win. But still we have one point and that is not good enough for Manchester United."

Van Gaal also refused to comment on speculation linking Real Madrid's Angel di Maria with an imminent move to the club.