The Vatican said Friday that Pope Francis is on a breathing machine after suffering a sudden respiratory episode during his hospitalization.

The development marked a setback in what had been two successive days of increasingly upbeat reports from doctors treating Francis.

Pope Francis is still critically ill as he battles double pneumonia, but his condition has shown a "slight improvement", the Vatican said on Monday.

The Vatican said Pope Francis remained in critical condition Monday but showed slight improvement in laboratory tests and resumed some work.

Pope Francis remains in critical condition, though he is showing “slight improvement” in some laboratory results, according to the Vatican. On Tuesday morning, the Holy See Press Office reported that Francis slept well overnight despite his serious condition.