Zohran Mamdani pledged to stand up to pressure from the Trump administration in his first press conference since winning the mayoral race on Tuesday.
The 34-year-old announced his transition team and said he would tackle the "twin crises" of "an authoritarian administration and an affordability crisis".
Trump has referred to the mayor-elect as a communist - a label that Mamdani rejects, and has implied the administration would withhold federal funding from New York City if he won.
The president hinted at a new political rivalry on Election Night, posting "AND SO IT BEGINS!" on his Truth Social account shortly after Mamdani won.
Trump has referred to Mamdani as "extreme," and Republican House Speaker Mike Johnson has said his party will tie Democrats to Mamdani's policies in next years' midterm elections.
