Jurgen Klopp rates Manchester City as one of the "strongest teams in world football" and acknowledges Liverpool will need to be at "110 per cent" to beat them.
Reigning Premier League champions City travel to Anfield for a top-of-the-table clash on Sunday, with the two sides locked on 19 points at the summit.
Liverpool have won each of the teams' last three meetings in all competitions, beating them 4-3 at home in the top flight before running out 3-0 and 2-1 victors in the Champions League.
But, despite that impressive run following the 5-0 defeat at the Etihad Stadium in September 2017, Klopp is adamant he has not stumbled upon a formula that guarantees a win over City.
He said: "We beat City three times last season and not once after any of those games did we go into the dressing room and think, 'Now we know how to beat them.'
Klopp: "There's a lot of games to be played. It's a home game against , it's tough. They never give up." October 5, 2018
"City never lose their focus. They have all my respect for sure. We have to be really spot on, at our best to keep them away from our goal and to be a threat ourselves.
"It will be hard work, no problem with that, everybody knows it. We need to be 100 per cent if not 110 per cent to beat City.
"It's a home game against Man City, they are all tough. Even the 3-0 in the Champions League was tough, and in the 4-3 they were really good.
"They had won 60, 70 games in a row, or that's how it felt. They never gave up and we had to score exceptional goals to win. Even at 4-1 [down] they never gave up.
"They are one of the strongest teams in world football, but in an outstanding stadium, with fantastic supporters against a really good football team, which we are, let's try again."
