Volkswacht Bodensee - Pope in surprise St Peter's visit a day after meeting King Charles

The public appearance and brief impromptu meeting with the royal couple come as the 88-year-old pontiff recovers at the Vatican from a bout of pneumonia that kept him in hospital for over five weeks.

On Wednesday afternoon, the pope entered the sprawling basilica to admire restoration work that is wrapping up and greet some of the workers, Italian news agency ANSA said.

"There were two young restorers... one of them saw the pope and greeted him from afar, so he told her to come closer to thank her and shake her hand," wrote ANSA.

The young woman replied "that she was sorry that her 'hands were cold' but the pope wanted to shake them anyway", the agency reported.

On Tuesday afternoon, the pope met privately with King Charles and Queen Camilla for 20 minutes, despite Buckingham Palace having earlier cancelled a planned official audience due to the pontiff's frail health.

It was the first meeting between Charles, the head of the Protestant Church of England, and the pope, who leads the world's Catholics, since the monarch ascended to the throne in 2022.

Francis offered his congratulations to the royal couple, who celebrated their 20th wedding anniversary Wednesday, the palace and the Vatican said.

During the encounter, the king -- who is receiving treatment for cancer -- and the pope also exchanged well-wishes for each other's health, the Vatican said.

"Their majesties were delighted the Pope was well enough to host them -- and to have had the opportunity to share their best wishes in person," a Buckingham Palace statement added.

Charles, 76, has been suffering from an unnamed cancer for more than a year and less than two weeks ago he was briefly admitted to hospital after experiencing side effects from his treatment.

He was out of action for a matter of days before resuming his official engagements on April 1.

Francis, who almost died twice during his treatment for double pneumonia, has been in convalescence since his return to the Vatican on March 23.

Despite being ordered to rest and recover for two months, the Argentine made an unexpected appearance in St Peter's Square last Sunday at the end of a mass.

On Tuesday, the Vatican said that Francis's voice and mobility were improving, raising hopes that he may take part in upcoming Easter celebrations.

He has been using a cannula -- a plastic tube tucked into the nostrils -- to help him breathe, notably at night, but was not wearing one in the picture released Thursday.

R.Kloeti--VB