Francis is being treated for pneumonia, a complex infection and kidney problems that have left him in critical condition.

Pope Francis, hospitalised in critical condition with pneumonia in both lungs, spent a peaceful night and was "resting" Monday, the Vatican said amidst global concern over the pontiff's health. An initial bronchitis diagnosis developed into double pneumonia and on Saturday the Vatican warned for the first time that his condition was critical.

The Vatican described his condition as critical for the first time on Saturday, reporting that the 88-year-old Francis needed supplemental oxygen and blood transfusions after a "prolonged asthma-like respiratory crisis.