Former US President Barack Obama has criticised attempts to stoke political divisions in the wake of the killing of Charlie Kirk.
At an event in Pennsylvania on Tuesday, Obama warned that the US was facing a political crisis of the sort that we haven't seen before. He said he did not know Kirk and disagreed with many of his views, but called the killing horrific and a tragedy.
He criticised Donald Trump's remarks towards his political opponents and pointed to previous Republican presidents who, he said, emphasised national unity in moments of high tension, US media report.
In response, the White House called Obama the architect of modern political division.
Kirk, 31, died of a single gunshot wound while speaking at Utah Valley University in Orem on 10 September.
On Tuesday, Tyler Robinson, 22, was formally charged with Kirk's murder, weapons offenses and other charges. Prosecutors said they would seek the death penalty.
Utah County Attorney Jeffrey Gray said Robinson had sent text messages which allegedly said he shot Kirk because he had enough of his hatred.
Before Robinson was captured, top Trump allies pinned blame for the killing on left-wing activists and rhetoric from Democratic lawmakers and their supporters.
Attorney General Pam Bondi has suggested that the administration will crack down on hate speech – although there is no specific US hate speech law. Vice-President JD Vance has led calls to expose people who celebrated or condoned Kirk's killing or were critical of him after his slaying.
Speaking in Erie, Pennsylvania, Obama emphasised that, at moments like this, part of the job of the president is to pull people together. He urged Americans to respect other people's right to say things that we profoundly disagree with.
Obama praised Utah Governor Spencer Cox, a conservative Republican, for showing that it is possible to disagree while maintaining a basic code of engagement in public debate. He also endorsed the response of Pennsylvania Governor Josh Shapiro, a Democrat, whose official residence was firebombed earlier this year.
The former president contrasted those reactions with comments made by Trump and his allies.
In a statement to the BBC, a White House spokesperson rejected the allegations and accused Obama of stoking division while he was president, saying that he used every opportunity to sow division and pit Americans against each other.