Italian President Sergio Mattarella has formally opened the 25th Winter Olympics in Milan and Cortina d'Ampezzo.

Mattarella opened the Games during a three-hour ceremony in Milan's San Siro stadium which highlighted Italian history and lifestyle and featured top acts including Maria Carey and Andrea Bocelli.

The ceremony was not limited to Milan but also held in Cortina, with the Olympic cauldron to be lit at both venues as well and the parade of nations also taking place in Livigno and Predazzo for logistical reasons.

The February 6-22 Games bring together around 2,900 athletes from 92 countries who will compete for 116 gold medals. They are in first Games in Italy and the Alps since Turin 2006, and the third snow and ice Games in Italy, with Cortina hosts for the first time in 1956.