Elizabeth Kim

Mamdani, who focused on public transit during his campaign, arrived at his swearing-in ceremony by subway.

He took the oath of office shortly after midnight, standing inside an abandoned subway station near City Hall.

Mamdani is now the city's first Muslim and Asian American mayor.

He's promised to deliver a bold affordability agenda that includes a rent freeze for stabilized tenants, free and fast buses, and universal child care.

For NPR News, I'm Elizabeth Kim in New York.