"I am happy to have signed for the biggest club in France and I never doubted that the negotiations would have a happy ending," the 28-year-old told L'Equipe.
"They showed such determination to sign me. If I had been forced to stay at Juve I would not have done so willingly.
"This will be a very interesting challenge. I was willing to take a pay cut to be here because I want to play regularly and regain my place in the national side."