"I'm proud to announce that I've signed a new long-term contract with Liverpool," he said on Instagram. "I'm buzzing. All the hard work has paid off.
"There's nothing I want more than to win trophies and be successful with this club. I'm grateful to God for this opportunity. I want to thank the fans, players and coaching staff.
"My family have been there for me throughout my whole life and without them this wouldn't be possible."
