Pope Leo touched down in Uruguay on Friday, opening a 12-day South America tour that will take in Argentina and Peru. The 71-year-old pope's Uruguay visit comes just three weeks after he underwent lung cancer surgery, and is the first stop on a papal trip across a region tied closely to his own life.

A trip three weeks after surgery

The leader of the world's 1.4 billion Catholics told reporters on the plane that he was glad to have arrived.

He said he wanted to bring a "message of hope in today's world." Asked about his recovery, the pope described himself as "in fairly good shape" following his surgery, and acknowledged the doubts that surrounded the trip.

"I know some people were doubtful about this trip taking place," he said, adding that he was convinced it had to go forward. Doctors gave the pope the all-clear to travel, and the Vatican said no special medical measures were necessary beyond the standard care that accompanies every papal trip.

On the flight, Leo also addressed his decision to vote by mail in the US midterm elections, making him the first pope ever known to vote in a political election. "I'm proud to be an American and to exercise the right" to vote, he said. The Church's first US-born pope has repeatedly clashed with US President Donald Trump over the Middle East war.

Montevideo programme and security

Uruguay, Latin America's most secular country and one of the wealthiest, has mobilised some 5,000 police officers and 1,000 soldiers for the visit. The programme in the capital includes:

• •A ride along Montevideo's waterfront promenade in a custom-made popemobile
• •A meeting with left-wing President Yamandu Orsi and the reception of the keys to the city
• •Masses in the cities of Paysandu and Florida, where tickets quickly ran out

Cardinal Daniel Sturla, Archbishop of Montevideo, pointed to "widespread interest in the pope's visit that goes well beyond the confines of the Catholic Church."

A secular host with tensions on the agenda

Uruguay legalised euthanasia last year and sits at odds with the Church on same-sex marriage and abortion. Leo is expected to appeal to protect life as well as traditional family values during his stay.

Mental health may also feature, particularly during a visit to the Casavalle neighborhood in Montevideo, which is notorious for high levels of poverty and extreme violence.

Argentina and Peru: a double homecoming

He will travel on Sunday to Argentina, the homeland of his predecessor Pope Francis, who disappointed many Argentinians by not returning during his papacy. Leo said he was going to visit Argentina "with great joy", calling it the country where Francis "did not manage to go."

Vatican expert Christopher White sees the 12-day papal trip as a double homecoming of sorts. "History's first Latin American pope, Francis, never returned to his homeland. Leo, a Peruvian citizen, now carries forward that legacy," White said. The pope holds joint US and Peruvian citizenship, having spent almost two decades in Peru as a missionary, where he lived his former life as Robert Francis Prevost.

Leo arrives in Peru on Wednesday, and White called the arrival "a moment full of symbolism and emotion." The pope has referred to Peru as "one of my many homes," saying he was looking forward to seeing "old things, new things and most of all the people."

Preparations there are already visible. In Lima, vendors are selling Leo T-shirts and rosaries, bakeries are selling Leo bread, and women serving time in prison have been making dolls modelled on him. In the port city of Callao, which the pope is due to visit, a 14-metre (46-foot) statue of Leo has gone up.

The Peru leg of the pope's South America tour will take him to the former Inca capital of Cusco and the Amazon rainforest, and includes everything from a supper with priests from his old diocese of Chiclayo to a private visit to a chapel he helped rebuild.

The pope travels on Sunday to Argentina, with the Peru leg beginning on Wednesday, including stops in Cusco, the Amazon rainforest and his former diocese of Chiclayo.