The new Barca midfielder said: "Henry is my friend. We spent two years together at Arsenal, we understand eachother quite well and I am very happy to be reunited with him here."
Hleb continued: "Moving to Barca is a great opportunity for me. I love the club and I want to try to win as many titles as possible.
Asked about fellow new signings Daniel Alves and Seydou Keita, Hleb added: "All the players are incredible and will be very important.
"In addition, we have a new coach and I think that with all these changes we can play very good football and win titles."