President Trump signaled Wednesday evening that he is willing to threaten New York City with the loss of federal funding if its newly elected mayor pushes ahead with a sweeping tax on wealthy second home owners. The warning landed on Truth Social in response to a proposal unveiled by Mayor Mamdani and Governor Kathy Hochul this week—a plan that would roughly double property taxes for New York’s most expensive second homes valued at $5 million or more.

The so-called “pied-à-terre” tax would apply to properties exceeding $5 million, with the mayor’s team estimating it could generate up to $500 million annually in revenue. Roughly 13,000 properties—many owned by out-of-state buyers, foreign investors, and Wall Street elites—would be affected under the proposal.

In his Truth Social post, Trump framed the tax as part of a broader trend driving residents and businesses away from the city while warning federal support could be cut: “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.”

The threat arrives at a critical moment for New York City, which has long relied on federal dollars for counterterrorism, transit grants, FEMA reimbursements, and Medicaid flow-through programs. Mayor Mamdani’s administration argues the tax targets absentee luxury ownership to fund housing, transportation, and education without increasing city debt. However, critics warn the measure would not address New York’s spending challenges despite its projected revenue.

Industry analysts caution that such a levy could accelerate the exodus of high-net-worth families from Manhattan to states like Florida and Texas, which have recently launched aggressive campaigns to attract wealthy residents. The clash between President Trump and Mayor Mamdani is poised to become one of the year’s most significant political confrontations over fiscal policy and federal leverage.