President Trump on Wednesday evening signaled he’s willing to hit New York City right in the wallet if its newly elected mayor pushes ahead with a sweeping new tax on the wealthy. The warning came after Mayor Mamdani and Governor Kathy Hochul unveiled a plan this week that would roughly double the property tax on New York’s most expensive second homes.

The so-called “pied-à-terre” tax would apply to second homes in the city valued at $5 million or more, with the mayor’s team estimating it could generate as much as $500 million in annual revenue. Roughly 13,000 properties — many owned by out-of-state buyers, foreign investors, and Wall Street executives — would be affected.

In his Truth Social post, Trump framed the new tax plan as part of a broader pattern he believes is driving residents and businesses out of the city. He warned that federal money flowing to New York could be on the chopping block.

“Sadly, Mayor Mamdani is DESTROYING New York! It has no chance! The United States of America should not contribute to its… TAX, TAX, TAX Policies are SO WRONG. People are fleeing. They must change their ways, AND FAST.” — President Donald J. Trump

The threat lands at a critical moment for New York City, which has long relied on federal dollars for counterterrorism, transit grants, FEMA reimbursements, Medicaid flow-through, and other line items. Any meaningful reduction in federal support would force painful choices at City Hall.

Mayor Mamdani’s administration argues the pied-à-terre tax targets absentee luxury ownership, with proceeds earmarked for housing and infrastructure. Roughly 13,000 properties valued at $5 million or more would be affected, generating an estimated $500 million annually.

Critics argue that even a half-billion-dollar tax haul won’t fix a city they say has a spending problem rather than a revenue problem. They warn that once the city establishes double taxation on second homes over $5 million, the threshold could quietly slide downward — first to $3 million, then $2 million, and eventually extending to primary residences of anyone deemed “rich enough” by the political class.

Real-estate analysts caution that such a tax could accelerate the exodus of high-net-worth families from Manhattan to states like Florida, Texas, and the Carolinas — regions that have spent years building aggressive campaigns to attract New York money.

The Trump-versus-Mamdani conflict is already shaping up as one of the year’s most defining political showdowns. On one side stands a mayor who ran openly as a democratic socialist and has quickly moved to target the city’s wealthiest residents. On the other, President Trump, who has repeatedly signaled his willingness to use federal funds as leverage against cities he views as hostile to taxpayers.