Arsenal have announced on their official website that the transfer of Alex Oxlade-Chamberlain to Liverpool is complete.
The Gunners reached an agreement with Chelsea but the player preferred to leave London to join Jurgen Klopp's squad.
The German was full of praise for the winger as he described him as a "very, very good player".
"I am really, really happy we have got Alex signed," Klopp told Liverpool's official website.
"Since the last game I have been waiting and hoping we could make this transfer - and when I got the news he was ours it was fantastic.
"I remember the first time I saw him play live - it was at Dortmund in 2014 and he came on as a sub that day and made a big impact. He stood out immediately because of his pace and skills and his attitude in such a big game for a young player; I remember him chasing back to make a brilliant challenge on Mkhitaryan in the box to save a certain goal.
"We won that game but lost the return match at Arsenal when he started and played well, I think he hit the post. Since then I have followed him and when I heard it may be possible to sign him I didn't need to think twice.
"I hear a lot of talk about positions but let's talk about the player; he is someone with really good abilities who always gives everything for his team. A player that is positive and willing to take risks to try and make positive things happen.
"He may still be young but he has a lot of experience in the Premier League, Champions League and for his country. Already he is a very, very good player and I think he has the mentality and desire to get even better - and that excites me.
"This is someone making a tough decision to leave one great club and come to another great club and I think he had many options, so to get him means I am delighted.
"He didn't make an easy decision but I think he made a great one to go on this journey with this squad of talented boys and our great supporters. I welcome him to the Liverpool family."