Concern for the ailing pope – leader of the world’s roughly 1.4 billion Catholics – has been pouring in from people of all religious backgrounds, according to Father John Muir, the vicar general of the Roman Catholic Diocese of Phoenix.

Pope Francis continued to improve from double pneumonia on Thursday, the Vatican reported, as he worked from his hospital room and visited his private chapel to pray. However, doctors stressed that he still needs several more days of clinical stability before they can reconsider their guarded prognosis.

Blood tests have confirmed an improvement, according to the Vatican's update. The slight kidney insufficiency detected a few days ago has receded, and Francis is continuing to receive respiratory physiotherapy.

Pope Francis had another "peaceful night" at Rome's Gemelli hospital and was resting on Wednesday morning as he continues to receive treatment for double pneumonia, the Vatican said.