The defender says it is an "honour" to play for the Catalans following his £15 million move and hopes training with "the best players in the world" can raise his own game
The centre-back agreed to join the Catalan giants last week and completed a £15 million move on Saturday.
And the 28-year-old believes that being amongst the best players in the world will allow him to improve, adding that it is an honour to join the club.
"It's a dream of many people to play at this club," he told Barcelona's official website. "You play with the best players in the world, and therefore it's a great honour to play with them here.
"It's good for me because I will be better player if I train every day with these players. I played at Arsenal and I know here is very different.
"We should be winning every game and I understand that there will always be pressure to perform well, and that's what I try to do.
"It's a different country, a different language and a different culture. It will not be easy. I'll have to adapt as quickly as possible and then we'll see."