Former President Donald Trump on Sunday called for unity and resilience in the aftermath of an attempted assassination against him, as the nation grappled with the implications of a gunman opening fire from a rooftop near a Pennsylvania campaign rally.

Meanwhile, President Joe Biden delivered a prime-time address, urging Americans to reject political violence and warning that “we can’t, we must not go down” that path. “It’s time to cool it down and we have a responsibility to do that,” Biden said, as AP reported.

A day after the shooting, the motive behind the gunman’s attack on the presidential candidate remained unknown, with investigators believing he acted alone before being killed by Secret Service agents. The incident, which left one bystander dead and two others critically injured, prompted President Biden to order an independent security review and the FBI to investigate as a potential act of domestic terrorism.

The shooting incident has sent shockwaves through the American political system, momentarily halting the intense and divisive 2024 presidential campaign.

Trump, the presumptive Republican presidential nominee, revealed that the upper part of his right ear was pierced by a bullet. Despite the incident, his aides reported that he was in “great spirits” and doing well. He arrived in Milwaukee on Sunday evening for the Republican National Convention, which begins Monday.

“I knew immediately that something was wrong in that I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin,” he wrote on his social media handle, adding, “Much bleeding took place.”

In a subsequent post on Sunday, Trump stated: “In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win.”

The rallygoer who was killed was identified as Corey Comperatore, a former fire chief from the area, according to Pennsylvania Governor Josh Shapiro. Shapiro added that Comperatore “died a hero,” sharing that his wife told him Comperatore dove on his family to protect them. The two wounded bystanders are reported to be in stable condition.

President Biden spoke briefly with Trump and was set to address the nation on Sunday evening. He emphasised that while the country will continue to debate and disagree, “we must unite as one nation to demonstrate who we are.”