Pope Francis, battling double pneumonia, remains in a critical condition and his prognosis is still guarded because of the "complexity" of his clinical condition, the Vatican said on Sunday.

The press office for the Vatican said Sunday that Pope Francis was able to rest overnight as he slowly recovers from double pneumonia after initially being hospitalized for bronchitis.

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.