Goals from Alfred N'Diaye and Oumar Niasse inflicted a second league defeat in three games for the Reds - a result that means they have now won only one of their last 10 matches in all competitions.
And although he insists that challenging for a Champions League spot rather than the title is becoming a more challenging target for Liverpool, Klopp admits his team deserve a scathing review for their display at the KCOM Stadium.
"We need to show much more consistency," he told a news conference. "The Champions League is an outstanding, big, big, big target – so many teams want to play there.
"To qualify for the Champions League in England is difficult because there are so many challengers, but on the performance of today we don't have to talk about this. We have to show now that we work, that we are really ready to go for everything.
"I can say it here, but it will not change a lot. We have to show it together. In a few days we have another opportunity to play and we need to show we are ready for all the other games.
"Even if we had won 2-1, I'd still be upset with the first half. I'm interested in the results. I'm interested in the performance because you can build on that. We will have to take all the criticism from everywhere. You can write what you want at the moment."
Liverpool dominated possession but produced little to threaten Eldin Jakupovic's goal despite mustering 22 shots across the 90 minutes.
Klopp felt his players did show improvement after the break but conceded it was "difficult to accept" allowing Hull to score from a corner and a simple counterattack.
"I want to play much better football with my team," Klopp said. "It's not about where you want to be, you have to show what you should reach in a season.
"We showed a few times, but obviously long ago we showed consistency and that's what we need to change immediately.
"We gave easy goals away. We didn't play the first half as we should have played, especially when you saw the second half. You think if you played from the beginning like this with the direction, speed, kind of greed and all that stuff then I think it would have been really difficult.
"Football under pressure is difficult because it's allowed to defend with a lot of legs in the box. They're not only a defending team, they play football and they are able to.
"There are spaces when you win the ball. We had these few moments but we were obviously not, especially in the first half, in the right mood. That's difficult to accept."