"It's a fantastic feeling to have agreed the deal. This is what I wanted. I want to see out the rest of my career with Liverpool," he told the club's official website.
"I have said all along that as long as the club wanted me then I would stay at Liverpool. I've been a fan all my life and it'll be fantastic at the end of my career to look back and say I have been with Liverpool all the way through.
"The main priority is to be successful and I want to achieve success at the club I love. If we can win more trophies together then I will be really happy.
"This news has given me a boost and hopefully it will help us in our remaining games. We've got big matches to play, all of them cup finals as we have to win them all to stay in the title race and go all the way to Rome."