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.

The health of Pope Francis, who has been hospitalized for over a week with pneumonia, worsened on Saturday, raising fears that the pontiff might not survive his struggle with respiratory infections.

The Vatican says Pope Francis is in critical condition after he suffered a long asthmatic respiratory crisis that required high flows of oxygen.