New York: At 34, Mamdani is also the youngest mayor New York has seen in generations, taking office with an ambitious agenda to tackle affordability in one of the world’s most expensive urban centres.

Mamdani took the oath at the decommissioned Old City Hall subway station, one of the city’s earliest underground stops known for its ornate arched ceilings. The ceremony was administered by New York Attorney General Letitia James, a close political ally, as Mamdani placed his hand on a Quran held by his wife, Rama Duwaji.

“This is truly the honour and the privilege of a lifetime,” Mamdani said after being sworn in.

The mayor will take the oath again later in the day in a larger public ceremony at City Hall, to be administered by US Senator Bernie Sanders, one of Mamdani’s political inspirations. The event will be followed by a public block party along Broadway’s famed “Canyon of Heroes,” a route traditionally reserved for ticker-tape parades.

Mamdani and his wife are set to move from their one-bedroom, rent-stabilised apartment in the outer boroughs into the official mayoral residence in Manhattan, as he assumes one of the most demanding and closely watched roles in American politics.

Born in Kampala, Uganda, in 1991 to acclaimed filmmaker Mira Nair and scholar-activist Mahmood Mamdani, the new mayor moved to New York City at the age of seven. He grew up in the post-9/11 era, later becoming a US citizen in 2018. After working on several Democratic campaigns, Mamdani was elected to the New York State Assembly in 2020, representing a district in Queens.

Running on a democratic socialist platform, Mamdani made “affordability” the central theme of his campaign. His key promises include free childcare, free public buses, a rent freeze for around one million households and a pilot programme for city-run grocery stores.

He takes office as New York shows signs of recovery from the COVID-19 pandemic, with violent crime down to pre-pandemic levels, tourism rebounding and unemployment returning to earlier lows. However, high living costs and rising rents remain a major concern for residents.

Mamdani also faces a challenging political landscape at the federal level, with Republican President Donald Trump having previously threatened to withhold federal funding from the city and floated the idea of deploying National Guard troops should tensions escalate.