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.

Pope Francis was in critical condition Saturday after he suffered a long asthmatic respiratory crisis that required high flows of oxygen, the Vatican said.