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.

Many who know him said that Francis, driven by a sense of mission and a discipline born of his early training, essentially worked himself into the hospital.

The Vatican announced Pope Francis was in critical condition after he suffered a severe respiratory crisis. Cardinal Timothy Dolan spoke about the situation.