Elon Musk is criticised for fueling political tension ahead of the election.
Elon Musk says he will attend Donald Trump's campaign rally in Butler, Pa., on Saturday. AFP

X marks the spot.

Elon Musk said he will attend Donald Trump's rally Saturday in Butler, Pa., where the former president will mark the first assassination attempt against him in July.

"I will be there to support!" the billionaire said in a posting on X, the social messaging platform he bought for $44 billion in 2022.

Trump, the Republican presidential nominee, said he would hold a rally at the Butler Farm Show grounds where he was grazed in the ear on July 13 by a shot from a gunman identified as Thomas Crooks, 20.

Crooks was immediately killed by a Secret Service sniper.

The event is expected to attract as many as 100,000 people, the Pittsburgh Post-Gazette reported.

The Secret Service, which was faulted for numerous failures in protecting Trump in July, is expecting up to 60,000 people, the newspaper said.

Trump was the target of a second assassination attempt on Sept. 15 while playing golf at his club in West Palm Beach, Fla., near his Mar-a-Lago home.

Secret Service agents found Ryan Routh lurking in the shrubbery with an AK-style rifle.

Musk, the CEO of Space X and Tesla, endorsed Trump just moments after the former president escaped the attempt on his life in Butler, saying the last time "America had a candidate this tough was Theodore Roosevelt."

He then posted the iconic photo of a bloodied Trump after the attempt, raising his fist in the air while urging his supporters to "fight, fight, fight."