President Joe Biden has urged Americans to allow the Federal Bureau of Investigation (FBI) to do its job and not assume the “motives and affiliations” of the shooter who attempted to assassinate former President Donald Trump at a Pennsylvania campaign event on Saturday.

“The FBI is leading this investigation, which is still in its early stages,” Mr Biden said in a press conference at the White House on Sunday. “We don’t yet have any information about the motive of the shooter.”

He added, “We know who he is. I urge everyone, everyone: Please don’t make assumptions about his motives or his affiliations. Let the FBI do their job.”

Mr Biden’s comments come in the wake of the assassination attempt on Mr Trump’s life during his campaign on Saturday in Butler, Pennsylvania. The incident has attracted global condemnation and left many speculating about the motive and political affiliations of the shooter.

The shooting saw a bullet pierce Mr Trump’s ear, leaving one dead and others injured.

“I want to thank the United States Secret Service and all of Law Enforcement for their rapid response to the shooting that just took place in Butler, Pennsylvania. Most importantly, I want to extend my condolences to the family of the person at the rally who was killed,” Mr Trump said after the incident.

The former American president also launched a fundraiser to support victims of the shooting on Sunday.

The shooter, who was identified as Thomas Matthew Crooks, a 20-year-old Pennsylvanian, was neutralised by Secret Service agents after he opened fire at the campaign event.

The incident has attracted global condemnation as U.S. authorities promise to investigate further. Footage showing Mr Trump with blood on his face and ear has gone viral, capturing the unsettling nature of the shooting.

Saturday’s shooting at Mr Trump’s Pennsylvania rally marked another incident in U.S. political history, adding to the list of presidential candidates who have been shot at.