Pope Francis was in critical but stable condition Tuesday as he worked from the hospital while battling double pneumonia, and the Vatican

Pope Francis is on the mend, showing a slight improvement in his health, which has allowed him to welcome a visit from Cardinal Pietro Parolin. They discussed important matters concerning the Vatican,

Pope Francis on Monday received a visit from Vatican Secretary of State, Cardinal Pietro Parolin, and the Substitute for General Affairs Mons. Edgar Pena Parra at Rome's Agostino Gemelli Hospital, the Vatican press office said in a bulletin on Tuesday.

Entrusting the pope "to the powerful intercession of most holy Mary," the cardinal said, "may she sustain him in this time of illness and help him to recover."

Cardinal Pietro Parolin, Secretary of State of the Holy See, presided over the rosary prayer in St. Peter’s Square, Feb. 24. A few thousand faithful gathered to pray for the recovery of Pope Francis,

The Vatican has detailed laws and rituals to ensure the transfer of power when a pope dies or resigns, but not when he is sick

The Vatican also released Francis' message for Lent, which runs from March 5 to April 17. The message, dated Feb. 6, encouraged Catholics to put themselves in the shoes of a migrant as an “examination of conscience.”

Pope Francis has also written a letter of resignation, to be invoked if he became medically incapacitated.

The Vatican has set in motion nightly prayers for Pope Francis in the hope that he might recover and get back to leading the Catholic Church.

The Vatican press office said Cardinal Parolin will lead a rosary for the pontiff in St. Peter's Square at 9 p.m. local time. The U.S. bishops urged Catholics to join that prayer at the same time, 3 p.m. on the East Coast.

The Vatican announced Monday that cardinals will lead a nightly Rosary in St. Peter’s Square for Pope Francis’s recovery, with the first prayer service scheduled for 9 p.m. Rome time on Monday evening.