The German complained about United’s defensive approach to their top-of-the-table clash and said their set up was ‘the worst thing you can face in the world’.
The Reds were unable to break down United’s defence throughout the match and extend their run without a Premier League goal to three games.
Defenders Luke Shaw and Victor Lindelof were standout performers for Ole Gunnar Solskjaer’s side, but Klopp was left unimpressed by the ‘world class’ United after the match.
‘We played football, tried to do it, force them back into their own box,’ he complained to BBC Sport.
‘The worst thing you can face in the world, in football is you play against a side with world-class players and they all defend with all they have, deep in the box and only counter-attack.
‘It’s really difficult – that’s the biggest challenge’
The best two chances of the match fell to United despite spending much of the evening defending and had just one third of possession.
Paul Pogba and Bruno Fernandes were unable to find a way past Liverpool’s Brazilian goalkeeper Alisson as they kept their place at the top of the Premier League.
Klopp added: ‘The performance was good, especially the first half was exceptionally good.
‘I think with all the things that were said before the game – ‘United is flying and we are struggling’ – and then playing this kind of game, I was really happy with that.
‘We tried it in the second half again but you cannot deny United for 95 minutes, especially with the counter-attacking threat they have.
‘They had two really good chances, I have to say, but we had our chances in the second half too.’