Brandon Johnson, the Chicago mayor, cast Pope Leo XIV as a powerful global ally on social justice, migration and reparations after meeting the Chicago-born pontiff at the Vatican, saying their shared roots and priorities could help amplify efforts to protect vulnerable communities.

“We are incredibly elated and proud of him,” Johnson told the Associated Press in an interview on Friday, a day after the meeting with the American pope in a private audience.

The mayor said it was comforting to know that someone who comes from the city of Chicago “can speak to justice” and defend “the most vulnerable among us”.

Johnson, a first-term progressive Democrat leading the third-largest US city, traveled to Rome with a delegation of about 50 local officials. He is a leading critic of Donald Trump and has applauded the pope for pushing back against the war in Iran and the US president’s immigration policies.

According to Johnson, the first thing Pope Leo asked him was: “How’s Chicago?”

“I was able to say that Chicago is strong and that we are transforming … He gave, I think, a great sort of pastoral nod, a pleasure to hear the incredible progress that … we’ve made,” the mayor said in a press conference.

“First of all, I thanked him for his courage,” Johnson said, adding: “I thanked him for his moral stance against these endless wars, and certainly talked about the vote that I took in city council a couple of years ago, calling for a ceasefire [in Gaza] and the releasing of hostages and our continuous stance on ending these illegal wars. We also talked about just elevating the awareness of the conditions that many people are living through, whether that’s in Chicago or Haiti, Venezuela, Cuba.”

He noted the meeting underscored areas of alignment between Chicago’s policy agenda and the pope’s emphasis on social justice, particularly on the legacy of slavery and the treatment of migrants.

Johnson said the pontiff’s apology for the Catholic church’s role in slavery reinforced his administration’s push for reparations, including efforts to fund a task force examining the lasting impact on Black Americans.

“The fact that the pope made a very clear declaration apologizing for the church’s role in slavery … is an affirmation to the work that we’re doing,” he said.

Johnson stressed the visit reflects an effort to position Chicago within a broader international push for human rights, with the pope’s global influence lending weight to the city’s agenda on justice, migration and reparative policies – and potentially extending that message well beyond the US.

Migration was also central to their discussion. Johnson said Pope Leo asked directly about conditions in Chicago following a US immigration crackdown and efforts to deport migrants.

“He wanted to know the conditions on the ground in Chicago … how we were responding,” Johnson said, adding the pontiff was aware of “the mass effort to deport immigrants from the city of Chicago and really around the country”.

Last year, Johnson signed an executive order directing the city to resist Trump’s immigration raids, including ordering all city departments to guard the constitutional rights of Chicago residents “amidst the possibility of imminent militarized immigration or national guard deployment by the federal government”.

Among the gifts brought to the pope were letters from families of detained immigrants, a Southwest community ICE watch pin, as well as an “Immigrants Make America Greater” hat from the Chicago sister cities international program, the Chicago Tribune reported.

Other gifts presented to the pontiff – a notable White Sox fan – included a White Sox hat adorned with the Italian flag, his parents’ diplomas from DePaul University, a Pope Leo Cubs jersey, and a range of memorabilia from community organizations and educational institutions throughout the city.

Since being elected last May, Pope Leo has gained widespread backing across the US particularly because of his refusal to acquiesce to the Trump administration and his criticism of the US-Israel war on Iran, which he said was being fueled by a “delusion of omnipotence”.

Trump, meanwhile, has personally attacked the pontiff, describing him as “weak on crime and terrible for foreign policy” earlier this year. Pope Leo dismissed the remarks, responding: “I’m not afraid of the Trump administration.”

In the wake of these exchanges, the pope has won over many Americans – Catholics and non-Catholics alike, who have hailed him as a “breath of fresh air”.

Earlier this week, Pope Leo used his first encyclical – a major papal text – to denounce artificial intelligence and “new forms of slavery” tied to the digital economy, calling for the “disarming” of AI.

He also warned of “a troubling revival of war as an instrument of international politics”, saying the technology was helping to facilitate the “normalisation of war”.