US President Donald Trump launched a scathing attack on New York City’s Democratic mayoral primary victor Zohran Mamdani on Sunday, labeling him as a “pure communist” and “radical leftist lunatic” in a television interview. Trump threatened New York would lose access to federal funds if Mamdani, a democratic socialist, “doesn’t behave himself.

Speaking on Fox News’ Sunday Morning Futures, Trump expressed alarm over Mamdani’s primary victory, which saw him defeat a scandal-plagued frontrunner. “I think it’s very bad for New York,” said Trump, who has deep roots in the city. “If he does get in, I’m going to be president and he is going to have to do the right thing or they’re not getting any money.”

Trump’s presidency has already threatened to cut off federal funding to Democratic-controlled cities, particularly those with sanctuary city policies. Mamdani has vowed to maintain New York’s sanctuary status, telling NBC’s Meet the Press that it allows undocumented residents to “get out of the shadows and into the full life of the city.

Responding to Trump’s attacks, Mamdani, a 33-year-old Ugandan-born state assemblyman, denied being a communist. “I’m fighting for the working people he claimed to support and has since betrayed,” Mamdani said, accusing Trump of focusing on his background to distract from policy discussions.

In spite of having a solid Democratic base, Mamdani will have tough competition in the general election. Mayor Eric Adams is seeking re-election as an independent candidate, and former Governor Andrew Cuomo can also be expected to join the fray as an independent candidate.