"RFK Jr. is a Democrat 'Plant,' a Radical Left Liberal who's been put in place in order to help Crooked Joe Biden, the Worst President in the History of the United States, get Re-Elected," President Trump wrote in an April 26 Truth Social post.

"A Vote for Junior' would essentially be a WASTED PROTEST VOTE, that could swing either way, but would only swing against the Democrats if Republicans knew the true story about him. Junior' is totally Anti-Gun, an Extreme Environmentalist who makes the Green New Scammers look Conservative, a Big Time Taxer and Open Border Advocate, and Anti-Military/Vet..."

"I lived with RFK Jr. in New York and watched him convince Governor Cuomo to make Environmental moves that were outright NASTY," he wrote in another post.

"Upstate New York was not allowed to drill or frack as Ohio, Pennsylvania, and others ripped off New York Energy. Because of this, prices have skyrocketed all over that part of the Country, but especially Upstate New York and New England."

The former president pointed out that New York's energy costs are the "highest in the U.S." except for California. President Trump insisted he prefers President Biden over Mr. Kennedy as the United States "would last a year or two longer prior to collapse - But it would be dead either way."

"I'd even take Biden over Junior," Mr. Trump added.

President Trump had criticized Mr. Kennedy in March along similar lines, calling him the "most Radical Left Candidate in the race" late last month. Calling RFK Jr. a "big fan of the Green New Scam, and other economy killing disasters," he suggested Mr. Kennedy could take away votes from President Biden.

Mr. Kennedy initially wanted to challenge President Biden for the Democratic Party nomination. However, he alleged that the Democratic National Committee (DNC) was "rigging the primary" by not allowing any challenge against the current administration. In October last year, he announced running for the 2024 presidential race as an independent.

RFK Jr. claimed in a social media post that the DNC attacked him as they feared he would be a "spoiler candidate" in the election. He said Democrats were spending "millions" to take down his campaign and that they "never expected" his movement to gain the momentum it has.