The former Manchester United and Real Madrid defender's move was announced last week.
At his presentation on Tuesday, Varane said: “What convinced me was the overall project.
“It was a very interesting project, but also an opportunity for me to help the club. My personal ambition was to come here and try a new challenge, to learn from it.”
On coach Cesc Fabregas, he continued: “Obviously, Cesc was a very important person in that process, but it is a new challenge, with a new league, let’s just say there were all the elements required for me to come here.
“We talked about football mainly. I liked his philosophy, the ideas he proposed, because we always did and still do have many ideas in common.
“Cesc is someone who likes to win, so there wasn’t too much that needed to be said.”