New York City Mayor Zohran Mamdani was inaugurated Thursday, pledging to govern as a Democratic Socialist and revive “the era of big government.”

He took the official oath with his hand on a Quran and later a ceremonial oath from Sen. Bernie Sanders.

Mamdani vowed to transform City Hall into a proactive government that serves all New Yorkers rather than wealthy interests and said he would remain steadfast in his progressive principles.

He criticized reliance on the private sector and promised to use government power to improve residents’ lives, Breitbart News has reported.

Rep. Alexandria Ocasio-Cortez praised Mamdani’s election as marking a new, far-left era for the city focused on the working class.