Pope Francis and Argentina's President Javier Milei are due to hold their first official talks on Monday, as the two leaders seek to mend fences amid the explosive economic situation in their native country.
The political newcomer is on his first visit to Rome since being elected in October on a wave of anger over decades of economic crisis.
He plans to meet Monday morning with the pontiff -- whom he has lambasted in the past -- with meetings to follow during the day with Italy's Prime Minister Giorgia Meloni and President Sergio Mattarella.
The 53-year-old libertarian economist and self-described "anarcho-capitalist" had sharp words for his compatriot during his election campaign, including calling him an "imbecile".
But the two men were all smiles Sunday during a brief meeting following a papal mass at the Vatican's St Peter's Basilica to canonise Argentina's first female saint, where Milei gave the 87-year-old a bear hug.
The president's meeting with the pope comes against the backdrop of major political uncertainty in Argentina, where Milei has embarked on massive economic deregulation by presidential decree.
Some 40 percent of the country falls under the poverty line, while crippling inflation soars over 200 percent.
But throughout his papacy, Francis has railed against the inequalities generated by free markets, calling for the protection of society's most vulnerable.
Since his election, Milei has devalued the peso, cut state subsidies and scrapped hundreds of rules.
His reform package hit a roadblock last week, however, when parliament sent it back to committee for a rewrite, prompting Milei to lash out at his opponents, calling them "criminals" and "traitors".
During their meeting Monday, the president and pontiff -- both of whom were born in Buenos Aires -- will likely discuss a possible papal trip to Argentina.
After accusing the pope last year of interfering in politics, Milei softened his tone after the pontiff called to congratulate him on his election win, encouraging Francis to return to Argentina for the first time since becoming pope in 2013.
During Sunday's mass, at which 18th-century missionary Mama Antula was canonised, Francis again made a plea on behalf of society's most marginalised.
"How many suffering men and women do we meet on the sidewalks of our cities," he lamented during his address.
Mama Antula, a consecrated Jesuit laywoman born Maria Antonia de Paz y Figueroa, is considered a champion of human rights from the period when Argentina was a Spanish colony.
She was beatified in 2016.
Milei, who made an official visit to Israel before coming to Italy, is travelling with his spiritual adviser, a rabbi.
Although from a Catholic family, he has expressed his fascination with Judaism and has been studying the Torah.