Liverpool withstood a first-half siege from City at the Etihad Stadium as Mohamed Salah and Roberto Firmino both scored after half-time to guide the Reds to a 5-1 win on aggregate over Pep Guardiola's side.

The Merseyside club are now in the semifinals of the Champions League for the first time since the 2007-08 season.

Speaking at his postmatch news conference, Klopp said: "This league is unbelievably strong, this competition is unbelievably strong. You cannot imagine how much intensity you feel before a game like this.

"I really think they are the best team in the world at the moment but I knew we could beat them. We completely deserve to be in the semifinals.

"Everybody wrote me a message -- 'I will watch the game here, I will watch the game there, I will have a beer together with friends...' I would really like to do that as well, to drink a beer and watch a Champions League game. Unfortunately, it is always work.

"It's all good but it's not that you can enjoy it completely, but I don't care who is in [the competition]. We are here and we deserved it, and I am really happy about that.

"So far, we fought for each opportunity to get it -- and then to use it is so hard. But that's what we will do. The other teams will have their targets as well when we meet them in the semis; I think they are not without ambitions."

Liverpool recovered from going 1-0 down inside two minutes as a result of Gabriel Jesus' goal and escaped going further behind in the first half as Bernardo Silva struck the post before Leroy Sane controversially had a goal ruled out for offside.

"We've matured constantly, that's true," Klopp said. "The boys get more and more used to situations like this. If you could say anything bad about us in the past, the last few months, then it's that on a good day we beat everybody and on an average day we lose with cheap goals.

"Obviously we have worked on that. It's all about confidence, being convinced about what you are doing and stuff like that. We did it, but on the other side it is always like this.

"Yes, if the ball is here or there around the box, in the box, you need to defend it, but it should not happen that often. That only works if you have the ball and then you have to do something with it.

"We are still in a development phase, that's how it is, but already a good team."

Liverpool could be pitted against Roma in the last four of Europe's premier club competition in Friday's draw after the Italian side defied the odds to beat Barcelona on Tuesday night.

Klopp initially thought it was a joke when somebody informed him that Eusebio Di Francesco's side had overcome a 4-1 deficit to go through on away goals against the likely La Liga Champions.

"I walked up the stairs and somebody told me [Roma had gone through] -- I really thought it was a joke," Klopp said. "Not that I don't respect Roma, the absolute opposite. They have a fantastic team -- Edin Dzeko, wow. They lost Mo Salah and they are in the semis, that's quite a big thing.

"I cannot say anything about the game, I didn't expect it before the game but I knew it was possible.

"This competition is quite fair and I really think a normal final would have been Manchester City against Barcelona, and now they are both out.

"But there will still be two other really strong teams in there plus Roma and us. We will see what happens but that's not the thing I have to think about tonight."