Pope Leo XIV returned to public duties on Sunday, addressing thousands of faithful from the window of the Apostolic Palace in St. Peter’s Square just four days after surgery to remove a malignant tumor from his right lung. The 71-year-old pontiff, who underwent a 90-minute operation on Tuesday to excise the lower lobe of his lung, thanked the crowd for their prayers and said he would “gradually resume my activities, always with God’s help and your prayers.”

The pope’s voice sounded strong as he led the traditional Angelus blessing, the same weekly event during which he had announced the discovery of the nodule a week earlier. He expressed “particular gratitude to the doctors, nurses and all the staff at Gemelli hospital” and added that the experience had made him feel “especially close to those facing illness and infirmity.” Histological tests on the tumor and related lymph nodes are still underway to determine if further treatment, such as chemotherapy or immunotherapy, is needed.

The crowd, estimated by Vatican media at 15,000 to 30,000, erupted in cheers and applause. A delegation from Africa in Rome for a Catholic congress danced and ululated after the blessing. Alain Kalembu of the Democratic Republic of the Congo said, “He was always in our prayers when he was sick, and we are happy to see him today. This is an expression of our joy.” American tourists, including Marla Marsala of Michigan, also gathered to pray with the pope. “I am just happy that we are praying with him today instead of for him, like we were before,” Marsala said.

Leo was discharged from Gemelli Hospital on Saturday, earlier than initially expected. His surgeon, Dr. Stefano Margaritora, told Vatican News that the pope’s recovery was progressing well and that there were “no clinical reasons why” a planned Nov. 6-17 trip to Uruguay, Argentina and Peru should not proceed. The journey includes a dozen flights and visits to high-altitude locations, such as Cusco, Peru, at 3,400 meters. Margaritora said he expected Leo to recover fully in “another 10 days or so.”

The pope’s rapid return to public life followed a week of global concern after he revealed the diagnosis of adenocarcinoma, the most common type of lung cancer. Visitors in St. Peter’s Square on Sunday described his reappearance as a sign of resilience. Claire Holland from Jacksonville, Florida, called it “very blessed” to witness his return. “I think there have been millions and millions of prayers,” she said. “He is a strong, determined man.”