A defiant Curtis Sliwa on Tuesday forcefully rejected the thundering calls for him to end his long-shot bid for New York City mayor.

“Let’s be very clear: I am not dropping out, under no circumstances,” the Republican nominee said during a press conference on the Upper West Side. 

“I’ve already been offered money to drop out, I said ‘no,’” he said.

Sliwa’s resistant stance came the day after his boss at WABC radio, owner of the station and influential Republican John Catsimatidis, issued a public plea for Sliwa to drop out of the race and unite behind Andrew Cuomo.

Forces seeking to stop socialist Democratic nominee Zohran Mamdani’s ascendance to City Hall have for months been calling on the crowded field of candidates to coalesce behind one person with the best chance of beating him.

But the urging from Catsimatidis moved the pressure campaign to a new, fever-pitch level, especially since the billionaire businessman had previously said he wouldn’t call Sliwa out publicly.

Sliwa, a friend of the grocery store magnate, has a day job as a shock jock on Catsimatidis’ WABC radio, but is on leave from the station while campaigning.

The Guardian Angels founder — who has claimed he’s turned down $10 million in “bribes” for him to drop out — stubbornly stood his ground, while taking aim at the donor class for trying to meddle in the heated race.

“The billionaires have led the parade and they’ve been wrong every step of the way,” Sliwa told reporters, touting the slew of high-level Republicans who have backed him.

He’s been endorsed by former Mayor Rudy Giuliani and ex-Gov. George Pataki, as well as by prominent New York GOP Reps. Elise Stefanik and Mike Lawler.

Sliwa also continues to have the backing of the five New York Republican Party county chairs — including  Catsimatidis’ daughter, Andrea, who chairs Manhattan’s GOP committee.

“Republicans across every borough stand united behind Curtis Sliwa for Mayor of New York City,” the five county chairs said in a joint statement Tuesday. 

“Republican voters are not going to vote for Andrew Cuomo,” their statement said.

“Curtis Sliwa is our candidate, the credible leader who will defeat the radical left and restore safety, affordability, and common sense to City Hall,” the chairs said, calling him “our candidate” to defeat Mamdani on November 4.

But Sliwa is still running without the backing of the most prominent member of his party: President Trump.

The president has behind the scenes tried to put his finger on the scale in his hometown’s mayoral election by angling to winnow the field down to a two-man race, sources have said.

Speaking from the Oval Office Tuesday afternoon, however, Trump appeared resigned to the fact that Mamdani would be elected — as he repeatedly slammed the upstart Democratic Socialists of America member as a “communist.”

“I don’t know if I want to get involved,” Trump said when asked if he will call publicly for Sliwa to drop out.

“It’s not looking too good for Cuomo either, but maybe if he [Sliwa] dropped out, maybe Cuomo would have a little bit of a chance. Because it looks like the lead is, it’s not a great lead, but it’s big enough that he should be able to win,” he added.

“I look at the polls and it looks like we are going to have a communist as the mayor of New York,” Trump said.

“It’s going to be interesting. But here’s the good news, he’s going to have to go through the White House.”