Jurgen Klopp claimed Manchester United have assembled one of Europe's strongest squads as he warned Liverpool not to underestimate Sunday's opponents.

The bitter rivals drew 1-1 at Old Trafford in October – the only time this season Liverpool have dropped points in the league – but are separated by 27 points going into the reverse fixture at Anfield.

Liverpool are expected to take another step towards a maiden Premier League title but manager Klopp urged his players to treat Ole Gunnar Solskjaer's side with caution.

United edged a strong Wolves outfit 1-0 in the FA Cup in midweek and have the chance to close to within two points of fourth-placed Chelsea.

"As a fellow manager it is easy to see the progress they make, although others on the outside are often not so quick to recognise," Klopp said in his club's matchday programme.

"They have recruited some exceptional players and the evolution of their squad makes them one of the strongest in Europe, I would say.

"Look at their talent from the keeper through to the forwards. They have world-class talent in that team and a squad full of match-winners. Big investment has resulted in a very strong group.

"Of course, looking to build something takes time. We know this ourselves. But they build with outstanding results and performances as a foundation.

"Their win this week in the FA Cup against Wolves was yet more evidence of how dangerous they are."

United's hopes of springing an upset will be pinned on repeating the kind of counter-attacking performance that brought Manchester City undone at the Etihad Stadium in December.

However, Klopp insisted there was more evidence than just the Manchester derby to indicate his team are in for a difficult 90 minutes.

"I have no idea how this contest has been billed externally but I also couldn't care less," the German said.

"I know how we have prepared and I know the respect we will show United."

"If anyone thinks that win at City is the only signpost of danger, then they are silly and underestimating," he added.