Lovren is being linked with Zenit St Petersburg this week.
"Dejan has played outstanding games for us," said Klopp. "He is a very important part of the squad. We have four centre-halves and we play usually with two of them, but we have needed all four - always.
"Dejan has a very important role for us. He has played in a Champions League final, in a lot of big games, he is a very reliable player.
"There is a value to his experience, absolutely. Since I've been in here, Dejan was always either in the team, close to the team or not available. There was never anything else, we have never had any problems.
"There is nothing to discuss in public about his contract situation. The situation is absolutely clear - Dejan is a player of LFC and we need him.
"At this moment again, with Joel (Matip) injured, we have only three centre-halves, and Dejan had a little problem in recent weeks, not massive but is now available again.
"You need the quality we have at centre-half to be successful."