Pope Francis arrives to hold a mass at the Jasna Gora Monastery in Czestochowa, Poland on July 28, 2016. Pope Francis visits Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / POOL / STEFANO RELLANDINI

Pope Francis in his popemobile greets the faithful on July 28, 2016 in Czestochowa, Poland, as he arrives at the Jasna Gora Monastery. Pope Francis heads to Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / AFP PHOTO / WOJTEK RADWANSKI

Nuns react as Pope Francis arrives at the Jasna Gora Monastery on July 28, 2016 in Czestochowa, Poland. Pope Francis heads to Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / WOJTEK RADWANSKI

TOPSHOT – Pope Francis is helped onto his feet after falling on the stairs during a mass at the Jasna Gora Monastery in Czestochowa, Poland on July 28, 2016. Pope Francis visits Poland for an international Catholic youth festival with a mission to encourage openness to migrants. / AFP / FILIPPO MONTEFORTE