Pope Leo XIV's recovery from surgery to remove a lower lobe of his lung is "progressing as expected", his doctors have said.

The 71-year-old pontiff has started to walk and has "resumed a normal diet" following the roughly 90-minute procedure, the medics said in an update shared by the Vatican.

The Pope was diagnosed with lung cancer after the surgery at Rome's Gemelli Hospital on Tuesday afternoon, which the Vatican said had been "successful" and proceeded without complications.

Blood tests and an X-ray early on Wednesday showed his recovery was "proceeding normally", the doctors said, and he has also undergone respiratory physiotherapy.

The whole lower lobe of the Pope's right lung was removed "to ensure the procedure was radical", the Vatican said following the surgery.

"After the operation, the Pope awoke normally and returned after a brief period of observation to his room," it said earlier, before spending a "peaceful night" at the hospital.

The pontiff is expected to remain there for about a week as he recovers.

He had announced that he would be admitted for the operation during his weekly Sunday prayers, telling the crowd in St Peter's Square that doctors had found a "well-contained" nodule on his lung "at an early stage" and advised him to have it removed.

Nodules are quite common and not necessarily cancerous, but after it was examined the medical team confirmed it was, "as suspected by pre-operative tests", the Vatican said. He was diagnosed with lung adenocarcinoma.

A Vatican source told news agency AFP that further tests were carried out to see whether the cancer had spread.

The Vatican has stressed that the Pope, who is generally thought to be fit, had no symptoms of infection or illness.

The news has shaken Catholics worldwide, many of whom will have recent memories of Pope Francis's hospital visits.

Pope Leo's predecessor, who died last year, also had part of his lung removed in his youth before suffering a series of respiratory infections later in life.

Adenocarcinomas develop in cells that produce mucus and are one of the most common types of lung cancer.

The long-term prognosis depends on a number of things, including the stage of the cancer when identified and the person's overall health. The earlier it is spotted, the better, and treatments have improved over the last few decades.

Some adenocarcinomas are picked up early - before symptoms develop - during routine tests. At later stages, lung cancer can cause a persistent cough, breathlessness, fatigue and weight loss.