Donald Trump kicked off Monday morning by turning his attacks towards former 2024 rival Kamala Harris just hours after Joe Biden's devastating cancer diagnosis was made public.

The president is demanding a 'major investigation' into Harris after she doled out massive amounts of campaign cash for major celebrity appearances from the likes of single-name icons Beyonce and Oprah.

Trump claims that Harris' lofty spending for performances at her events equates to using donations to pay for endorsements, which is illegal.

Still, the slew of celebrity appearances and mini concerts, including from Bruce Springsteen, did not help Harris get any closer to getting promoted to the Oval Office.

Trump accused Harris of an 'illegal election scam' in a follow-up post and specifically called out hit R&B artist Beyonce and claimed she was paid $11 million just to endorse Harris.

Records from the Federal Election Commission (FEC) do not show such a payment being made by the Harris campaign to Beyoncé.

'According to news reports, Beyoncé was paid $11,000,000 to walk onto a stage, quickly endorse Kamala, and walk off to loud booing for never having performed, not even one song!' Trump lamented. 'Remember, the Democrats and Kamala illegally paid her millions of Dollars for doing nothing other than giving Kamala a full throated endorsement.'

The posts on Monday came the day after former President Biden's office announced that he was diagnosed with an 'aggressive form' of prostate cancer.

Trump posted on Sunday to his Truth Social well wishes for Biden's recovery.

'Melania and I are saddened to hear about Joe Biden's recent medical diagnosis,' the president wrote. 'We extend our warmest and best wishes to Jill and the family, and we wish Joe a fast and successful recovery.'

But the next morning Trump was back to his usual social media antics and turned his attacks to Biden's former No. 2.

'How much did Kamala Harris pay Bruce Springsteen for his poor performance during her campaign for president?' he questioned in his Truth Social post. 'Why did he accept that money if he is such a fan of hers? Isn't that a major and illegal campaign contribution?'

'What about Beyonce?' the president continued. 'And how much went to Oprah, and Bono??'

He insisted: 'I am going to call for a major investigation into this matter. Candidates aren't allowed to pay for endorsements, which is what Kamala did, under the guise of paying for entertainment.'

A representative for Bono told Daily Mail that, as an Irish citizen, he has never endorsed a U.S. presidential candidate. 

In addition, Bono did not 'take part in any events for the Harris campaign.'

Trump often had celebrities who supported him appear or perform at his campaign rallies. This included Kid Rock, Jason Aldean, Billy Ray Cyrus and God Bless the USA singer Lee Greenwood. He even had the Village People perform their hit song Y.M.C.A. at his inaugural rally.

His post, however, suggests that Trump did not pay for these performances – at least not from his campaign funds.

Trump said on Truth Social that Harris was desperate to get these 'expensive' and 'unpatriotic' performers to come to her events to 'artificially build up her sparse crowds.'

'This was just a corrupt and unlawful way to capitalize on a broken system,' Trump concluded.