The Reds are in sixth place in the Premier League table and six points behind fourth-placed Manchester City in the race to secure a spot in next season’s Champions League.
Klopp lost his first final as Liverpool manager after a penalty shootout defeat by City in the League Cup showpiece at Wembley last month.
However, the Reds can book their place in the Europa League quarter-finals with a last-16 win against Manchester United over two legs.
Dortmund chief executive Watzke is confident Klopp will make Liverpool a success if the 48-year-old is given time by the club’s owners.
“It took Jurgen three years,” Watzke told The Sun. “Before he came we finished 13th and then sixth in his first season. The next year we were fifth and the following year, as the team grew, we won the title.
“People at Liverpool, the owners, believe in him and he has the time. It’s better now to beat Manchester City and lose to Swansea than vice versa.
“It’s easier to find the style to beat Swansea than to beat Man City. Jurgen is a fantastic coach and if the owners of Liverpool believe in Jurgen they will have success.”
Liverpool will host United in the first leg of their Europa League last-16 clash at Anfield on Thursday night.
The Reds make the return trip to Old Trafford on 17 March as the bitter rivals come face-to-face in Europe for the first time.
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