Pope Francis is showing a "good response" to his treatment in hospital for double pneumonia and his overall condition is gradually improving, the Vatican said on Saturday.
Francis, 88, has been in Rome's Gemelli hospital for more than three weeks with a severe respiratory infection that has required continuously evolving treatment.
"The clinical condition of the Holy Father in recent days has remained stable and, consequently, indicates a good response to the treatment," the latest detailed medical update said.
The pope, it said, has continued to have no fever and his blood tests have remained stable.
Although the doctors said they had seen "a gradual, slight improvement" in the pope's overall condition, they maintained a guarded prognosis "in order to ensure these initial improvements continue in the coming days".
The pope is continuing to receive oxygen to help with his breathing, the Vatican press office said. During the day, he uses a small oxygen hose under his nose. At night, he has been using non-invasive mechanical ventilation as he sleeps.
Francis has experienced several bouts of ill health over the last two years and is prone to lung infections because he had pleurisy as a young adult and had part of one lung removed.
Double pneumonia is a serious infection in both lungs that can inflame and scar them, making it difficult to breathe.
Francis has not been seen in public since entering hospital, his longest such absence since his papacy started nearly 12 years ago.
The pope's doctors have not said how long the treatment might last. He will miss a weekly prayer with pilgrims for the fourth week in a row on Sunday, the Vatican said.
Doctors not involved in Francis' care have said the pope is likely to face a long, fraught road to recovery, given his age and other long-standing medical conditions.
The tone of the updates from the Vatican has been cautiously upbeat in recent days, after the pope suffered what was described as two episodes of "acute respiratory insufficiency" on March 3.
Groups gathered outside Gemelli hospital throughout the day on Saturday to pray for Francis. They placed candles, prayer beads and other items at the base of a statue of the late Pope John Paul II, who was treated at the facility many times over his 1978-2005 papacy.
Maria Neve, from Naples, Italy, left a small bouquet of yellow flowers. "He is an incredible person who gives so much to others, and we, in turn, must give back to him," she said.
Francis, who is known to work himself to exhaustion, has continued to work from hospital. On Saturday, the Vatican announced the appointments of four bishops that would have required his approval.
Francis on Saturday also sent a message to an anti-abortion group in Italy which was undertaking a pilgrimage to the Vatican.
The message, read aloud to the group by Cardinal Pietro Parolin in St. Peter's Basilica, was signed by Francis with a note to say it was sent "from Gemelli hospital".