In a way, it must be tough being king. One day, you’re lauded by the US president, applauded by Congress and served spring-herbed ravioli and parmesan emulsion on a golden plate.

The next, you’re essentially snubbed by the mayor of New York City, who makes it clear that a) he does not want to meet you, and b) you should return a diamond that your ancestors took from a 10-year-old Indian boy.

That’s the situation King Charles III faced in the US’s largest city on Wednesday, as the monarch arrived to attend a wreath-laying ceremony to honor 9/11 victims. The trip came a day after Charles received plaudits for his turn in Washington DC, his easy rapport with Donald Trump and well-pitched speech to Congress seen as a step towards repairing the UK-US relationship.

But while Charles may have charmed the prestige-loving Trump, gifts of gold and wisecracks about the Boston Tea Party were never likely to appeal to Zohran Mamdani, New York’s democratic socialist mayor who was elected on a promise to rein in elites, and whose father is one of the world’s experts on the effects of colonialism.

Mamdani’s eagerness to avoid Charles was clear, his team distancing themselves from the king from the moment the 9/11 ceremony, at the World Trade Center, was announced. “The mayor will not meet privately with King Charles. But the mayor will be at the wreath laying ceremony today,” Joe Calvello, the mayor’s press secretary, said in a terse statement on Wednesday morning.

It was hardly the treatment Charles is accustomed to, but as the day unfolded it seemed he may have gotten lucky by avoiding a private audience. Asked on Wednesday morning what he would say to Charles if they were to spend time together beyond the ceremony, Mamdani said: “If I was to speak to the king separately from that, I would probably encourage him to return the Koh-i-Noor diamond.”

The 106-carat diamond, which currently sits in the crown worn by the queen mother, has been the subject of an ownership dispute since it came into the possession of Queen Victoria in 1849. Critics say the diamond, which is the size of a hen’s egg, was immorally taken from Duleep Singh, a 10-year-old maharajah whose kingdom was seized by the British.

Buckingham Palace declined to comment on whether they would return the diamond.

At the World Trade Center, Charles and Camilla were accompanied by Mike Bloomberg, who was mayor of New York from 2002 to 2013, rather than Mamdani, as they toured the site’s memorial pools and laid a wreath. In spite of all the diamond talk, when Charles did meet Mamdani, they appeared to strike up something of a bond, the pair shaking hands and smiling during a short conversation.

In the wake of the shooting at the White House correspondents’ dinner over the weekend, security in lower Manhattan was tight, with at least one subway stop closed and building access strictly monitored. Press access was severely limited, meaning Charles faced no questions about the friendship between his brother Andrew, the former prince, and the convicted sex offender Jeffrey Epstein, but the king may have been reminded of the relationship during his New York visit: Charles laid his wreath less than a mile from the Metropolitan Correctional Center, where Epstein killed himself in 2019 while awaiting trial, and a few subway stops south of Epstein’s former home in Manhattan’s Upper East Side, where Mountbatten-Windsor was a frequent guest.

The royal family made a reported £12m payment to Virginia Giuffre, who survived Epstein’s abuse and who brought a civil case against Mountbatten-Windsor accusing him of sexual assault. Mountbatten-Windsor made no admission of liability and has denied Giuffre’s claims. Giuffre died by suicide last year.

Charles has faced criticism during his US visit for refusing to meet Epstein’s victims, and he certainly made no mention of the controversy as he left the 9/11 ceremony. He was whisked to an after-school, urban farming project in Harlem, with Camilla traveling to the New York Public Library, where she planned to gift a stuffed kangaroo to the library’s collection of soft-toy Winnie-the-Pooh characters.

As the king made his way across town, New Yorkers were largely nonplussed, except for being irritated by the disruption to travel.

“It’s like a CIA operation down there,” said Danica Parry as she emerged from an underground subway stop close to the 9/11 site.

She added: “I was walking with people, and they’re all showing their IDs at these different exits. And this lady was like: ‘Do you know what’s going on?’ I said: ‘I have no idea what’s going on, but I think we’re supposed to take this exit.’”

Parry eventually found her way to street level. She wasn’t too upset – “this is like a weekly occurrence,” she said – although she was unexcited by the visit of the royals.

“I’m pretty neutral about them. Yeah, they don’t impact my life. They kind of do their own thing,” Parry said. She said she did not think the US should be ruled by a hereditary monarch.

“No, I am not into monarchies at all. Neither abroad nor domestic,” she said.