The Vatican said on Saturday that Pope Francis' health had deteriorated over the past 24 hours and for the first time described his condition as "critical", reporting he had needed supplemental oxygen and blood transfusions.

Pope Francis, who has been hospitalized for over a week, is in critical condition after a "prolonged asthma-like respiratory crisis," the Vatican said Saturday. The pope is "more unwell than yesterday," the Vatican said in a statement.

Doctors on Friday said the 88-year-old Francis is "not out of danger" ​and that the main threat facing him would be the onset of sepsis.