The new Pope Leo will officially be sworn in at a mass on May 18.
The criticism he directed at Trump's government was published before he was elected on Thursday.
In a post on the social media platform X in February, Robert Prevost, who the Pope is actually named, linked an opinion piece with the headline "JD Vance is wrong: Jesus does not ask us to rank our love for others". It mainly deals with Trump's government's promised mass deportations of undocumented immigrants.
On another occasion, Prevost re-published a post criticizing the US's migration policy and deportation of undocumented migrants with the words "Don't you see the suffering? Doesn't it disturb your conscience?"
The new Pope was born in Chicago in the USA but has lived in Peru for many years and is also a Peruvian citizen.
On his first working day as Pope, on Friday, Leo XIV will celebrate mass in the Vatican. Then, he will again meet the cardinals who voted for him during the conclave.