"They showed me a repression filmed a week ago... Workers. People demanding their rights in the streets," the pope said in Spanish at an event with social movements from across the world.

"The police pushed them back. With the most expensive thing there is: top-quality pepper spray," Francis said, according to a video of the event published by the Vatican.

He did not name Argentina or its president by name, but appeared to be referring to a September 12 Buenos Aires protest over a pension increase veto, during which police used tear gas and plastic bullets.

Francis's comments made headlines in Argentina on Friday.

"Why didn't they have the right to claim what's theirs? Because they were undisciplined? Communists? No, not at all," the pope said during the meeting at the Holy See's department for economic, labour and social justice issues in Rome.

"The government did not budge. Instead of paying for social justice, it paid for pepper spray," Francis said.

Since taking office in December, Milei has applied a drastic austerity programme in a bid to rein in chronic inflation and decades of government overspending.

The International Monetary Fund has worsened its outlook for Argentina's economy, which it now expects to contract by 3.5 percent this year, after a 1.6-percent decline in 2023.

Francis received Milei for the first time at the Vatican in February.

The two leaders were both born in Buenos Aires but have very different views of the world.

One is a liberal economist and climate change sceptic, the other a champion of the poor who regularly attacks the power of financial markets and blames humankind for global warming.

In the past, Milei has sharply criticised the pontiff, accusing him of political interference and calling him an "imbecile" who "promotes communism".

He has since softened his tone and invited him to visit Argentina. Francis has not returned to his homeland since becoming head of the Catholic Church in 2013.

The pope said earlier this month that plans for a visit were not yet definite.

"I would like to go there, but it is not yet decided. There are several things to resolve first," he told a press conference.