Pope Francis, who the Vatican said is responding well to treatment for pneumonia, thanked his doctors and healthcare workers on Sunday as he missed delivering a fourth straight Angelus prayer in person.

The 88-year-old, in Rome's Gemelli hospital since 14 February, issued a written Angelus in which he thanked those who volunteer to help others in need, praising their "closeness and tenderness."

"I too experience the thoughtfulness of service and the tenderness of care, in particular from the doctors and healthcare workers, whom I thank from the bottom of my heart," he said.

"We need this, the 'miracle of tenderness' which accompanies those who are in adversity, bringing a little light into the night of pain," he said in the text published by the Vatican.

The leader of the world's 1.4 billion Catholics has spent time at the Gemelli before, notably for colon surgery in 2021 and a hernia operation in 2023.

This hospitalisation has been more serious, however, with Francis suffering several respiratory crises, prompting fears the road to recovery would be long, or might force the elderly pontiff to resign.

On Saturday, the Vatican said the pope appeared finally to be responding well to treatment and had seen "a gradual, slight improvement", marking several days without crises.

Though the pope does not have a fever, his doctors want to see more positive results "in the coming days" before giving a prognosis, an evening medical bulletin said.

On Sunday, the Vatican press office said the pope was "stable."

"The doctors confirmed the situation remains the same as yesterday," and the pope had seen "slight improvements... in a complex overall picture," it said.

The next bulletin is expected on Monday afternoon.

'Given so much'

Francis has been alternating rest, prayer and bits of work when he feels up to it.

On Sunday he received Italian Cardinal Pietro Parolin, the Vatican's secretary of state, and Edgar Pena Parra, a Venezuelan archbishop who is also a senior Vatican official.

He continued his treatment, doing both his physiotherapy and his breathing exercises, the press office said.

Francis also followed spiritual exercises being held at the Vatican via video link, though while he could see participants, they could not see the pope, it said.

People who gathered in St Peter's Square on Sunday, where Francis would usually stand at a Vatican window to read the Angelus to crowds below, said his presence was sorely missed.

"He is a wonderful person who has given so much and I hope that he can return as soon as possible," said Diana Desiderio, who volunteers with the civil protection agency in the Italian city of Pescara.

She and fellow volunteers are praying that Francis will "return to the window again and bring peace and serenity to everyone, because we need it," she told AFP.

The pope ended the Angelus with his traditional call for peace in conflicts, "in particular in tormented Ukraine, Palestine, Israel, Lebanon, Myanmar, Sudan and the Democratic Republic of Congo."

He said he had "learnt with concern of the resumption of violence in some areas of Syria, I hope that they cease definitively, with full respect for all ethnic and religious components of society."

Catholics have also been gathering at the Gemelli hospital to pray for Francis or leave flowers, candles and cards.

Giuseppe Antonio Perazzo, 74, was at the hospital for the second Sunday in a row, dressed smartly in a suit and tie in the hope that the pontiff might appear at the window.

A sign he propped up in sight of the windows of the pope's rooms urged the Argentine pontiff — a notoriously headstrong patient — to "keep doing what the doctors and nurses tell you to do."