Klopp has hailed Joel Matip as "one of the best, incredible pieces of business we've done".
Matip joined Liverpool on a free transfer from Schalke in the summer of 2016, and will be staying until 2024 after agreeing a new long-term deal.
“As the team has evolved and become better, so too has Joel.
“I said earlier this year that signing a player of his quality is one of the best, incredible pieces of business we've done since I started here – and I think now that's something everyone can see.
“I knew what he was capable of from seeing him up close in the Bundesliga and we were certain he could bring that performance level to us."