Palm Beach, Florida - Donald Trump has reportedly been so frustrated about his flailing presidential campaign that he has started using insulting terms to refer to his challenger Kamala Harris in private.

According to a recent report from The New York Times, Trump has been fuming behind closed doors as his campaign struggles to come up with an effective approach to take on Harris.

The Republican candidate has become so frustrated that two sources claim they have "repeatedly" heard him call Harris a "b****" on several occasions.

Trump campaign spokesperson Stephen Cheung has denied the allegation.

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"That is not language President Trump has used to describe Kamala, and it's not how the campaign would characterize her," he told Politico.

The New York Times report also revealed that Trump had one of his aides recently send "angry text messages" to one of his largest campaign donors, Miriam Adleson, to complain that her Super PAC is being run by RINOs – or Republicans in name only.

The shocking details emerged as Trump and his running mate, JD Vance, have spent the past few weeks attacking Harris' gender and race, a strategy that has played poorly so far.

On Sunday, Trump shared his reaction to the times article on his Truth Social platform, in which he described the outlet as a "crooked newspaper" that is "losing readers at a record level."

"Their stories about me are highly inaccurate, and their polling is even worse," the former president wrote.

"They are a big reason for the DECLINE OF NEW YORK CITY, which the entire World is watching with shock and sorrow! Its only hope is that I get elected President."

"I will fix it, and fix it fast!" he added.

While reports claim he has been seething in private, Trump told a crowd during a rally on Friday that he'd "rather run against" Harris, as he believes she will be "easier to beat" than President Joe Biden.