House Speaker Mike Johnson
House Speaker Mike JohnsonReuters/Michael Brochstein/SOPA Images

US House Speaker Mike Johnson on Saturday night announced an investigation into the assassination attempt on former President Donald Trump.

“The House will conduct a full investigation of the tragic events today,” he said in a statement posted to social media site X.

“The American people deserve to know the truth. We will have Secret Service Director Kimberly Cheatle and other appropriate officials from DHS and the FBI appear for a hearing before our committees ASAP,” added Johnson.

Earlier, US Attorney General Merrick Garland vowed to invest all possible resources in the investigation of the assassination attempt on Trump.

"I have been briefed on the shooting at former President Trump's rally, and have briefed the President. The FBI, ATF, U.S. Attorney's Office for the Western District of Pennsylvania, and the Department's National Security Division are currently working with the Secret Service as well as state and local law enforcement partners on the ground in Butler, Pennsylvania," Garland said in a statement.

"My heart is with the former President, those injured, and the family of the spectator killed in this horrific attack," he added.

"We will not tolerate violence of any kind, and violence like this is an attack on our democracy. The Justice Department will bring every available resource to bear to this investigation," stated Garland.

Trump was discharged from hospital in Pittsburgh on Saturday night after being hit in his ear from the shooting during a rally in Butler, Pennsylvania.

His campaign indicated that he plans to take part in the Republican convention in Milwaukee.

US President Joe Biden, speaking from Delaware, commented on the incident and, when asked if it was an assassination attempt, replied, “I don’t know enough to – I have an opinion, but I don’t have any facts. I want to make sure we have all the facts before I make any more comments.”

The White House later said that Biden had spoken to Trump.