Ahead of the game, Porto boss Sergio Conceicao claimed semi-final qualification for his side will be tough because Liverpool are "the best in the world".
"He said we are the best team in the world?," Klopp questioned when asked on his thoughts by reporters.
"Yeah, sometimes we are really good and hopefully we can show it again. It's a compliment but we know we have a tough job to do.
"We are here to go to the next round. We have to fight really hard. Porto have won all their home games (in the Champions League) so far.
"Porto are a really good side. We need to play at our highest level because you cannot stand the power that they can create here."
The boss also provided an injury update on Joe Gomez, who travelled with the squad, saying: "His fitness levels are getting better and better. Can he start 90 minutes in a Champions League game? I'm not sure.
"But can he play whenever he is needed? Yes, yes. That is possible and that is the most important thing for us.
"Having a player with the quality of Joe... remember what a season he played until he got injured, that was incredible.
"We're really happy he is now on that level and he is here with us and what we do with that situation we will see tomorrow."