Pope Francis is resting, but remains "critical" with respiratory and kidney problems, more than a week after being admitted to hospital, the Vatican has said.

"The night went well, the Pope slept and is resting," a Monday morning statement said, after an update on Sunday said the Pope was still receiving high-flow oxygen therapy and had undergone blood transfusions.

Blood tests also showed he had "initial, mild, renal insufficiency" - a kidney problem - that is "currently under control", it said.

The Pope was admitted to Rome's Gemelli Hospital on 14 February after experiencing breathing difficulties for several days, where he was first treated for bronchitis before being diagnosed with pneumonia in both lungs.

On Sunday, the Pope's thrombocytopenia - a condition that occurs when the platelet count in the blood is too low - was stable, the statement said.

That morning, the Pope "participated in the Holy Mass, together with those who are taking care of him during these days", the statement continued.

The Vatican did not offer a prognosis, given the "complexity of the clinical picture".

On Saturday, the Vatican said that the Pope had experienced a respiratory crisis and was in a "critical" condition, but later on Sunday released an update that he had "not presented any further respiratory crises".

Earlier on Sunday, the Pope issued a statement asking Catholics to pray for him after he was unable to deliver the traditional Angelus prayer in person for the second week running.

The pontiff is particularly susceptible to pneumonia, an infection of the lungs that can be caused by bacteria, viruses or fungi, after he contracted pleurisy - an inflammation of the lungs - as a young man and underwent a partial lung removal.

The leader of the Roman Catholic church has been admitted to hospital multiple times during his 12-year tenure, including being treated for bronchitis at the same hospital in March 2023.

From Argentina, Pope Francis is the first Latin American, and first Jesuit, to lead the Roman Catholic Church.