Pope Leo's Mass at the Monumento de los Espanoles drew more than 2.5 million people. ( Reuters: Pedro Lazaro Fernandez )
Roughly 2.5 million people have attended a Mass on the streets of Buenos Aires with Pope Leo XIV.
The pontiff is conducting a tour of South America, where he previously spent decades as a missionary.
During his visit in Argentina, he appeared to criticise the economic policies of Javier Milei's government.
Buenos Aires officials said approximately 2.5 million worshippers have turned out for a vast public Mass by Pope Leo XIV, with pilgrims travelling from across Argentina and camping overnight to get a glimpse of the pontiff.
The event came as the Catholic leader gave a pointed criticism of the country's populist president, Javier Milei, rebuking his government's economic policies.
The gathering is tipped to be among the largest of Leo's 12-day Latin American tour. Crowds chanted "Ole, ole, ole, Leon, Leon" and waved yellow-and-white Vatican flags as they waited.
Some faithful travelled more than 1,000 kilometres to attend, while others kept vigil through the night along the capital's broad avenues.
As part of his South American tour, Pope Leo is making the first papal visit to Argentina since 1987. ( Reuters: Martin Cossarini )
Giant screens carried images of the pope's journey through the city as folk musicians performed and pilgrims sheltered from the spring sun under umbrellas.
"It's going to be unforgettable. It's going to be one of a kind," said health worker Marta Calderon, who camped out overnight to see Leo on the second leg of his Latin American tour.
Leo said in his sermon how happy he was to see Catholics in a region that has long been a stronghold for the Church but where it has been losing ground recently to fast-growing evangelical denominations.
Earlier, the Chicago-born pope visited the Pequeno Cottolengo, a home for abandoned people with disabilities in the Buenos Aires suburb of Claypole.
"It fills my heart with joy to celebrate … with you," said the pope.
"My visit to this land of Argentina has allowed me to see on your faces the enthusiasm of your faith."
Addressing residents, staff and volunteers, Leo said disabled people were "not a burden on society" but "a blessing."
"A nation's progress is also measured by how it welcomes all people with disabilities and particular needs," he said.
His remarks touched on a sensitive issue in Argentina, where disability organisations and Church leaders have voiced concern over measures affecting assistance programs under President Javier Milei's austerity drive.
A day earlier, the pontiff urged Argentinians to safeguard democracy and called on the Milei government to not punish the poor through harsh austerity measures.
The pope appears to be critical of the policies of Argentina's President Javier Milei. ( Reuters: Yara Nardi )
Mr Milei has been criticised within the country for subsidy cuts, public sector lay-offs and reducing welfare such as disability benefits.
He has also been accused of undermining Argentina's democracy through divisive rhetoric and attacks on the press.
"Efforts should be made to promote whatever creates opportunities, stimulates private initiative and ensures that economic growth also benefits those who are disadvantaged," Leo said, in a line that drew strong applause.
