Pope Francis had peaceful night in hospital - Vatican source

Pope Francis spent a peaceful night in hospital, a Vatican source said on Thursday, a day after the 86-year-old pontiff was hospitalized with a respiratory infection.

The source said the Vatican was expected to give an update on the pope's condition in the "late morning".

On Wednesday, the Vatican had said that Francis would have to stay for "a few days" at Rome's Gemelli hospital for "appropriate" medical treatment.

According to Italian news agency ANSA, nursing staff "are very optimistic" that, barring surprises, the pope could be discharged in time for Palm Sunday celebrations on April 2.

ANSA, quoting unnamed hospital sources, also said doctors had "for now" ruled out heart problems and pneumonia for Francis.

Palm Sunday marks the start of a hectic week of ceremonies leading to Easter Sunday on April 9, the holiest day in the Christian calendar, marking the resurrection of Jesus Christ.

Francis' health has attracted increased scrutiny in the last two years, during which time he has undergone colon surgery and begun using a wheelchair or a walking stick due to chronic knee pain.

His latest hospitalization has revived speculation over a possible resignation on health grounds, following the historic precedent of his late predecessor Benedict XVI.

Asked by Italian Swiss television RSI in an interview broadcast on March 12 what condition would lead him to quit, Francis said: "A tiredness that doesn't let you see things clearly. A lack of clarity, of knowing how to evaluate situations".