The left-back finalised the deal at the AXA Training Centre on Tuesday and spoke of his delight at doing so.
“Obviously when the negotiations started and it looked as if my future was going to be here longer term than what it was, then I think it’s no secret that I’m happy at this club,” Robertson told Liverpoolfc.com.
“I want to stay at this club for as long as possible and to extend my stay, it’s always a happy time for me, for my family. We’re settled here, we love everything about this football club and I’m glad that the journey is continuing.”
Watch in full: Andy Robertson on new contract
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Since joining the Reds from Hull City in the summer of 2017, Robertson has established himself as a core member of Jürgen Klopp’s champion side which has won the Premier League, Champions League, FIFA Club World Cup and UEFA Super Cup.
The 27-year-old has made 177 appearances for the club to date and was appointed captain of Scotland in September 2018.
He becomes the fifth member of Klopp’s squad to commit his future to Liverpool in recent weeks, following Trent Alexander-Arnold, Fabinho, Alisson Becker and Virgil van Dijk.
Robertson continued: “When you sign for a massive club, I still remember the day as if it was yesterday when I signed here and obviously you have ambitions to become a regular player for Liverpool, to win trophies for this club, to do everything else but the way it’s gone has been excellent.
“But since the very start of my career I’ve always been one to look forward: that’s in the past, that’s something that I can sit down with the people who want to listen to me when I’ve hung up my boots and retired and I can tell them all the stories that we’ve already made.
“But I’m certainly one, and I know a lot of people in this training ground just now are people to look forward and people [who want] to create more history, more stories. Hopefully people get bored of me when I’ve retired and I can sit down for hours and hours and tell them about all the stories!
“They’re certainly building up but I want to make more and obviously hopefully starting with this season. We want to achieve more, we want to bring hopefully more trophies, more happiness to this club.
“The only way of doing that is by working hard and having the same application that we have done since day one.”