The Pope has asked for prayers for his predecessor, Benedict XVI.
The request came at the end of Pope Francis' General Audience on Wednesday when he disclosed that the Pope Emeritus is "very ill".
Pope Francis asked the Catholic faithful to remember Benedict, 95, in their prayers.
"I would like to ask you all for a special prayer for Pope Emeritus Benedict, who is supporting the Church in silence," he said.
"Remember him - he is very ill - asking the Lord to console him and to sustain him in this witness of love for the Church, until the end."
The Holy See press office said on Wednesday that there had been "an aggravation" in Benedict's condition "due to advancing age".
He is under the supervision of doctors and his situation at the moment "remains under control", the press office said.
Benedict was Pope from April 2005 until his resignation in February 2013. Following his retirement he became Pope Emeritus. Since his retirement, he has lived in the Mater Ecclesiae monastery inside the Vatican.
The Holy See press office said that the Pope went to visit Benedict in the monastery after his general audience.
