The Vatican on Tuesday called the health condition of Pope Francis "guarded" and "complex" as he remained in a stable condition with double pneumonia, according to officials.

Pope Francis, batting double pneumonia in hospital, remained stable throughout the day on Tuesday and did not have any new respiratory crises, the Vatican said.Francis, 88, had suffered two episodes of what the Vatican described as "acute respiratory insufficiency" on Monday.

The frail 88-year-old Catholic leader suffered further setbacks in what has become a more than two-week battle to overcome a complex respiratory infection.