Mane agreed a new deal which will see him remain at Anfield until 2023, the same as fellow forwards Firmino and Salah.
Klopp insisted how it shows that players feel they can progress and develop at the club, rather than look elsewhere for the next step in their career.
“I’m really pleased, really happy about the fact he’s signed this contract. It’s really a big signing,” said Klopp.
“If a player is in a very good moment in his career and you can extend the contract, it’s more than just a signing, it’s a statement. I’m happy about that.
“It shows a bit of the change the club made in the last few years. A few years ago it constantly happened that players in a very good moment thought they had to leave the club to make the next step.
“Now our boys obviously think they can make the next step here. That’s good.”