A week after an assassination attempt left him with an injured ear, Donald Trump seemed to have fully regained his stride during a speech alongside his new running mate JD Vance.

With a skin-coloured plaster over the top of his right ear, Mr Trump was in jovial mood as he took to the stage in Grand Rapids, Michigan, to be greeted by chants from the crowd of “fight, fight fight”.

Noting the shooting happened “exactly one week ago”, he said: “I stand before you only by the grace of almighty God. I shouldn’t be here right now. Something very special happened.”

He sent his best wishes to the two people who were injured in the incident, and said 50-year-old firefighter Corey Comperatore, a spectator who was killed, “is a hero and we will carry his memory in our hearts”.

JD Vance claps as he looks at Donald Trump, with both men on stage in front of supporters
Donald Trump was welcomed on to the stage by his running mate JD Vance (Evan Vucci/AP)

Meanwhile in an interview to be aired on Monday night, Mr Trump said he was given no indication that law enforcement had identified a suspicious person when he took the stage last week at his rally in Butler, Pennsylvania.

Speaking to Fox News, Mr Trump said, “Nobody mentioned it, nobody said there was a problem” before a gunman opened fire in an attempted assassination.

“They could’ve said, ‘Let’s wait for 15 minutes, 20 minutes, five minutes, something.’ Nobody said. I think that was a mistake.”

Mr Trump also questioned the security lapses and how the 20-year-old gunman was able to gain access to the roof of a manufacturing building that was within 135 metres of the stage.

“How did somebody get on that roof? And why wasn’t he reported? Because people saw that he was on the roof,” Mr Trump said. “You would’ve thought someone would’ve done something about it.”

Close-up of Donald Trump, with a plaster visible on his right ear
Donald Trump had a skin-coloured plaster over the injury to his ear (Evan Vucci/AP)

Local law enforcement officers had seen the man and deemed him suspicious enough to circulate his photo, and witnesses reported seeing him scaling the building.

On Saturday night, close to an hour before Mr Trump took to the stage, supporters had filled nearly every seat in the 12,000-capacity Van Andel Arena.

Many wore red “Make America Great Again” hats and shirts with an image of Trump’s fist in the air after last week’s assassination attempt.

Excitement was palpable as people waited, with “U-S-A” chants breaking out frequently.

It comes as Republican officials, strategists and activists exude a confidence not seen in decades.

While President Joe Biden continues to face a growing chorus of Democrat voices calling for him to step aside, Republican officials confidently told how the party is more unified than ever.