New York mayor Zohran Mamdani pledges left-wing success after taking office

Zohran Mamdani promised Thursday to show left-wing politics can succeed as he took over as New York mayor for a term sure to see him cross swords with US President Donald Trump.

Thousands of people gathered in freezing conditions in the United States' largest city to celebrate the 34-year-old Democrat's inauguration after his impressive political rise from relative anonymity just a year ago.

"They want to know if the left can govern. They want to know if the struggles that afflict them can be solved," Mamdani said outside City Hall.

"We will do something that New Yorkers do better than anyone else: we will set an example for the world."

In the 24-minute speech, he added: "Beginning today, we will govern expansively and audaciously."

Mamdani, New York's first Muslim mayor, emphasized the cost of living issues that were central to his mayoral campaign, pledging to help those "betrayed by the established order."

Left-wing allies Senator Bernie Sanders and congresswoman Alexandria Ocasio-Cortez also spoke in front of some 4,000 ticketed guests.

"Thank you for giving us, from coast to coast, the hope and the vision that we can create government that works for all, not just the wealthy and the few," said Sanders, a former presidential hopeful.

At one point during his speech, the crowd broke into chants of "tax the rich." Mamdani wants to raise taxes on New York's wealthiest residents.

Thousands of people also thronged downtown Manhattan, many wearing yellow and blue beanies emblazoned with "Zohran," to watch the ceremony on large screens.

"This is the first time that either of us in our entire lives has felt some kind of political hope at all," 31-year-old Jacob Byerly, a scientist, told AFP alongside his wife Auburn.

- Ambitious agenda -

Mamdani, a self-described democratic socialist, comes to power at a time when Trump has pushed a hard-right agenda.

But it remains to be seen if Mamdani can deliver on his ambitious program, which envisions rent freezes, universal childcare and free public buses.

How Trump behaves could be decisive.

The Republican, himself a New Yorker, has repeatedly criticized Mamdani, but the pair held surprisingly cordial talks at the White House in November.

One flashpoint might be immigration raids as Trump wages an expanding crackdown on migrants across the United States.

Mamdani has vowed to protect immigrant communities.

Before the November vote, the president also threatened to slash federal funding for New York if it picked Mamdani, whom he called a "communist lunatic."

The mayor has said he believes Trump is a fascist.

Mamdani mentioned Trump only once in his speech Thursday while reflecting on the city's diversity, citing supporters of the president who also backed him in the mayoral vote.

- Symbolic inauguration -

The inauguration was jam-packed with symbolism.

New York Attorney General Letitia James, who successfully prosecuted Trump for fraud, performed a private midnight swearing-in at an abandoned subway station.

Mamdani's office said the understated venue beneath City Hall reflected his commitment to working people.

And in a first for the city, he used Korans to be sworn in as mayor.

Born in Uganda to a family of Indian origin, Mamdani moved to New York at age seven and enjoyed an elite upbringing with only a relatively brief stint in politics.

Compensating for his inexperience, he is surrounding himself with seasoned aides recruited from past mayoral administrations and former US president Joe Biden's government.

Mamdani has also opened dialogue with business leaders, some of whom predicted a massive exodus of wealthy New Yorkers if he won. Real estate leaders have debunked those claims.

As a defender of Palestinian rights, he will have to reassure the city's Jewish community -- the largest in the US -- of his inclusive leadership.

A small group of people holding Israeli flags appeared to protest Mamdani Thursday by blowing air horns during his speech.