The Swedish teen's move from FC Copenhagen was confirmed earlier this week.
Bardghji told Barca's media channels: “I have no words to describe the feeling I have right now. I'm very happy , it's a great day for me , for my family, and the people around me. It's a dream I've had since I was very little. It's spectacular to be here."
He becomes the fourth Swedish player in the club's history after Patrick Anderson, Henrik Larsson, and Zlatan Ibrahimovic.
“It's huge to be here. I think only two or three Swedish players had played for Barça before me. It's a huge deal. For me and for the Swedes, it's very important.”
He also said: "I'm a player who likes to have the ball and ask for it . I'm a player who makes my teammates better; I like to use my teammates.
"Last season the team was spectacular. I hope we can do it again this season and reach the final in all competitions; that's the goal . And individually, my goal is to gradually ease into the team, get playing time, and show who I am. I hope to contribute with goals and assists. Give my all so the club can achieve its objectives."