He told La Gazzetta dello Sport: "The opportunity arrived and I thought it was an excellent opportunity to take. I spoke to Mister Pioli before arriving at Milan and he explained to me how he likes to play, what his ambitions are for the season and how I could be useful to the team.
"It was a conversation that I really enjoyed and I was very enthusiastic. The club it's great, then the stadium, the history of the club, it was tempting to come to Milan. And then (Fikayo) Tomori was already here, I spoke to him before coming and he spoke very well about the club.
"It was a good opportunity so for me to come to play here."
He also said: "My teammates are brilliant. They are all fantastic, they are very talented. And obviously the technical staff is also excellent. Then the stadium and the fans: there it's an incredible atmosphere when we play at San Siro. Even in away games our fans make themselves heard, they give us all their support which is always very strong. It's really nice to play in these conditions.
"As soon as you wear the Milan shirt, for the history of the club, for the many great players who have worn it and for what this club has won, you just want to make Milan proud."