NEW YORK — In a historic moment for New York City, Zohran Mamdani took the oath of office as mayor just after midnight on Thursday. The ceremony unfolded at a decommissioned subway station in Manhattan, marking a new chapter for the city.

As a trailblazing Democrat, Mamdani’s swearing-in signifies a milestone as he becomes the first Muslim to lead America’s most populous city. During the oath, Mamdani placed his hand solemnly on a Quran, a symbol of his faith and commitment to serving all New Yorkers.

In his brief inaugural address, Mamdani expressed deep gratitude, stating, “This is truly the honor and the privilege of a lifetime.” His words resonated within the historic walls of the old City Hall station, a venue chosen for its architectural beauty and symbolic significance.

The private ceremony was conducted by Letitia James, the New York Attorney General and a political ally of Mamdani. The station, one of the first in the city’s subway history, is celebrated for its intricate arched ceilings and served as a poignant backdrop for Mamdani’s first public statements as mayor.

In his remarks, Mamdani highlighted the importance of public transit, calling the station a “testament to the vitality, health, and legacy of our city.” He also used the occasion to announce the appointment of Mike Flynn as the new commissioner of the Department of Transportation, underscoring his administration’s focus on improving the city’s transit infrastructure.

Concluding his speech with a touch of warmth and informality, Mamdani bid farewell to those present, saying, “Thank you all so much, now I will see you later,” before making his way up the station’s historic stairs, ready to embrace the responsibilities of his new role.

Mamdani will be sworn in again, in grander style, in a public ceremony at City Hall at 1 p.m. by U.S. Sen. Bernie Sanders, one of the mayor’s political heroes. That will be followed by what his office is billing as a public block party on a stretch of Broadway known as the “Canyon of Heroes,” famous for its ticker-tape parades.

Mamdani now begins one of the most unrelenting jobs in American politics as one of the country’s most-watched politicians.

In addition to being the city’s first Muslim mayor, Mamdani is also its first of South Asian descent and the first to be born in Africa. At 34, Mamdani is also the city’s youngest mayor in generations.

In a campaign that helped make “affordability” a buzzword across the political spectrum, the democratic socialist promised to bring transformative change with policies intended to lower the cost of living in one of the world’s most expensive cities. His platform included free child care, free buses, a rent freeze for about 1 million households, and a pilot of city-run grocery stores.

But he will also have to face other responsibilities: handling trash and snow and rats, while getting blamed for subway delays and potholes.

Mamdani was born in Kampala, Uganda, the son of filmmaker Mira Nair and Mahmood Mamdani, an academic and author. His family moved to New York City when he was 7, with Mamdani growing up in a post-9/11 city where Muslims didn’t always feel welcome. He became an American citizen in 2018.

He worked on political campaigns for Democratic candidates in the city before he sought public office himself, winning a state Assembly seat in 2020 to represent a section of Queens.

Mamdani and his wife, Rama Duwaji, will depart their one-bedroom, rent stabilized apartment in the outer-borough to take up residence in the stately mayoral residence in Manhattan.

Mamdani inherits a city on the upswing, after years of slow recovery from the COVID-19 pandemic. Violent crime has dropped to pre-pandemic lows. Tourists are back. Unemployment, which soared during the pandemic years, is also back to pre-COVID levels.

Yet deep concerns remain about high prices and rising rents in the city.

He’ll also have to deal with Republican President Donald Trump.

During the mayoral race, Trump threatened to withhold federal funding from the city if Mamdani won and mused about sending National Guard troops to the city.

But Trump surprised supporters and foes alike by inviting the Democrat to the White House for what ended up being a cordial meeting in November.

“I want him to do a great job and will help him do a great job,” Trump said.

Still, tensions between the two leaders are almost certain to resurface, given their deep policy disagreements, particularly over immigration.

Mamdani also faces skepticism and opposition from some members of the city’s Jewish community over his criticisms of Israel’s government.

The new mayor and his team have spent the weeks since his election victory preparing for the transition, surrounding Mamdani with seasoned hands who have worked inside or alongside city government.

That included persuading the city’s police commissioner, Jessica Tisch, to remain in her position – a move that helped calm fears in the business community that the administration might be planning radical changes in policing strategy.