Pope Francis will be meeting President Marie Louise Coleiro Preca on Saturday, his 80th birthday.

The two had already met (photo above) at the Vatican in 2014.

The Pope is marking his 80th birthday on Saturday with a morning Mass with his cardinals and an otherwise "normal" day of back-to-back meetings and audiences.

Francis isn't one to make a big deal about birthdays, but his decision to celebrate a special Mass in the Paoline Chapel of the Apostolic Palace suggests that even he recognizes 80 is a significant milestone. The chapel is where Francis spent his first minutes in prayer after being elected in 2013.

Francis then has a series of audiences, including with the president of Malta and the head of the Vatican's office for bishops, among others.

In the evening, he will be attending a concert to be given by Italian singer Claudio Baglioni at the Vatican, with proceeds going in aid of charity.

The birthday comes at a tumultuous time for Francis, as he presses economic reforms in the Vatican and endures criticism from conservatives over his pastoral approach.