The 17-year-old Frenchman joined the Italian club from French outfit Caen in August.
"Everton wanted me too, but I chose AC Milan and I am convinced of my decision," Niang told Sport Italia.
"Here at AC Milan all are kind with me. I'm the youngest and I pay respect to the whole group.
"I still have so much work to do and convince [coach Massimiliano] Allegri and I have to integrate well in Italian football."
Niang scored five goals in 30 Ligue 1 appearances for Caen last season.