Steven Roth, the chief executive of Vornado Realty Trust, used an earnings call on Tuesday to castigate Mayor Zohran Mamdani of New York for his “tax-the-rich” rhetoric, which he likened to a racial slur or a pro-Palestinian rallying cry.

“I must say that I consider the phrase ‘tax the rich’ — quote, tax the rich — when spit out with anger and contempt by politicians both here and across the country, to be just as hateful as some disgusting racial slurs and even the phrase, ‘from the river to the sea,’” Mr. Roth said, referring to the pro-Palestinian phrase that some Jews believe amounts to a call for ethnic cleansing.

Mr. Roth said “tax the rich” suggests that the wealthy are evil and should be made targets, and he criticized the mayor for singling out Kenneth C. Griffin, a fellow tycoon, in his campaign to force rich New Yorkers to pay more to support the city’s programs.

Mr. Roth said Mr. Mamdani’s decision to film a social media video celebrating Gov. Kathy Hochul’s proposed pied-à-terre tax in front of Mr. Griffin’s multistory penthouse — in a building developed by Vornado — was “dangerous” and an “ugly, unnecessary video stunt.”

Mr. Griffin, who bought the penthouse in 2019 for $238 million, had no immediate comment.

Joe Calvello, a spokesman for the mayor, said in a statement that “Mayor Mamdani wants all New Yorkers to succeed,” including Mr. Griffin, “who is a major employer in our city and a powerful figure in our economy.”

He added: “That does not negate the fact, however, that our tax system is fundamentally broken. It rewards extreme wealth while working people are pushed to the brink.”

Mr. Mamdani, 34, ran for office promising to fund expansive new government programs by raising taxes on wealthy individuals and major corporations. Mr. Roth spent heavily against Mr. Mamdani and in favor of his opponent, former Gov. Andrew Cuomo.

But in the face of a budget gap, Mr. Mamdani, a democratic socialist, has instead said those same taxes are also necessary to balance the books.

Unfortunately for Mr. Mamdani, New York City does not control its own tax policy, and Ms. Hochul, who is facing re-election this year, has steadfastly refused to accede to Mr. Mamdani’s demands. But facing pressure from Mr. Mamdani’s base, she did embrace a longstanding proposal to tax expensive second homes in the five boroughs.

And so, on April 15, Tax Day, Mr. Mamdani stood in front of Mr. Griffin’s building and claimed victory.

“This is an annual fee on luxury properties worth more than $5 million, whose owners do not live full-time in the city, like for this penthouse, which hedge fund C.E.O. Ken Griffin bought for $238 million,” Mr. Mamdani said in the video, which has since been viewed 52 million times.

At the time Mr. Griffin bought it, the condo was the most expensive home in America.

Mr. Griffin, who is worth an estimated $50 billion, responded on Tuesday with pique.

“It was creepy and weird,” Mr. Griffin said of Mr. Mamdani’s comments during an onstage interview at an investment conference in Beverly Hills, Calif.

Mr. Griffin elaborated in a separate Tuesday interview on CNBC.

Mr. Mamdani “seems to have forgotten that the C.E.O. of another American company was assassinated just blocks from where I live in New York,” Mr. Griffin said, referring to the 2024 killing of Brian Thompson, the chief executive of UnitedHealthcare.

A week after Mr. Mamdani’s video, Gerald Beeson, the chief operating officer of Citadel, Mr. Griffin’s hedge fund, sent out a letter to his colleagues suggesting that the company might mothball a new $6 billion skyscraper headquarters on Park Avenue that it had been planning to build with Vornado, denouncing Mr. Mamdani’s rhetoric and noting Citadel’s existing contributions to the city.

“Over the past five years, our principals and team members (including nonresidents) have paid nearly $2.3 billion dollars in city and state taxes, providing funds to support the city’s infrastructure, schools, parks and first responders,” Mr. Beeson wrote.

Mr. Griffin said on Tuesday that the development would “probably” move forward, even as he said that Citadel has also decided to expand its office space in Miami, a move for which he also blamed Mr. Mamdani.

“We will add far more jobs in Miami over the next decade as an immediate and direct consequence of the mayor’s poor decision here, with respect to his posting of that video,” Mr. Griffin said.

Mr. Griffin has a history of leaving major American cities in the dust. He famously left Chicago amid rising crime and a feud with Gov. JB Pritzker.

Possibly aware of that, Mr. Mamdani has since softened his rhetoric on Mr. Griffin, even thanking him during a recent Police Department ceremony for funding a memorial wall for fallen officers.

And Mr. Roth on Tuesday offered a note of modest praise for Mr. Mamdani.

“Our mayor is young, smart and energetic,” Mr. Roth said. “With a little tweak here, a little tweak there, his leadership could make this great city even greater.”

But Mr. Griffin deserves an apology, Mr. Roth argued.

“The rich, whom the politicians are targeting, started with nothing, are the epitome of the American dream,” he said. “They are at the top of the great American economic pyramid for a reason. They should be praised and thanked.”

Rob Copeland contributed reporting.