This photo taken and handout on April 4, 2025 by The Vatican Media shows Pope Francis during a surprise appearance at the end of a mass for the sick and healthcare workers as part of the Jubilee Year in The Vatican.  Handout / VATICAN MEDIA / AFP

Pope Francis was "happy" to get out and about this week but while his health is improving, it is too soon to confirm his participation in Easter celebrations, the Vatican said Friday.

The 88-year-old Catholic leader, who is recovering from life-threatening pneumonia, has appeared at three unscheduled events in recent days -- including a surprise visit to Saint Peter's Basilica on Thursday -- despite doctors urging him to rest.

"The pope was taking a walk yesterday morning, he asked to extend the walk by going to pray in the basilica," Vatican spokesman Matteo Bruni told reporters at a briefing.

Francis, who remained seated in a wheelchair throughout, surprised a family of tourists and workers engaged in restoration work when he suddenly appeared, without his papal garb.

The Argentine's head was uncovered and he wore a long-sleeved top, black priest trousers and a striped poncho or blanket instead of his traditional white vestments, according to a video published by ANSA news agency.

He was wearing a cannula -- a plastic tube tucked into the nostrils -- to help him breathe, but looked cheerful and stopped to say hello to a child.

"He was happy to go to the basilica and greet people," Bruni said.

Bruni confirmed the pope's outing was an impromptu one that caught some Vatican officials off guard, saying: "Sometimes things are born out of a desire to surprise, and they surprise us too."

The quick trip to the basilica followed an unscheduled private audience with King Charles III and Queen Camilla on Wednesday, and an unexpected appearance in Saint Peter's Square on Sunday at the end of a mass.

Francis, leader of the world's 1.4 billion Catholics since 2013, returned to the Vatican on March 23 after five weeks in Rome's Gemelli hospital.

On Friday, the Vatican said his voice and mobility were improving, but warned it was too early to say if he will take part in next week's Easter celebrations.

"There are improvements (in his health) that you have been able to notice with the outings in the past days," Bruni said.

However, "we are not making any particular forecasts for Holy Week", he said, adding that it depended not only on the pope's health but also "on the weather".