US President Donald Trump will lead tributes to Charlie Kirk at a huge stadium gathering to honour the young right-wing influencer slain in America's latest spasm of political violence.
Mr Trump waited his turn to address the crowd, hearing speeches from Secretary of State Marco Rubio, Defence Secretary Pete Hegseth and others as the memorial got under way.
"You thought you could kill Charlie Kirk? You have made him immortal," top Trump adviser Stephen Miller said. "You have immortalised Charlie Kirk, and now millions will carry on his legacy."
Among other speakers were right-wing media personality Tucker Carlson, Trump's Chief of Staff Susie Wiles and Director of National Intelligence Tulsi Gabbard.
The event was being hosted by Turning Point USA, the hugely influential youth political campaign group founded by Mr Kirk that is now run by his widow, Erica Kirk.
At the event, Mr Trump was seen sitting beside billionaire backer Elon Musk, whose acrimonious departure from the White House after his brief tenure overseeing the Department of Government Efficiency (DOGE) was not apparent as the two men chatted.
Thousands of people lined up in the pre-dawn dark hoping to get into the 63,000-seat American football stadium hosting the service to honour the young Republican star - a close ally of the president and credited with helping him get re-elected last year with his outreach to young Americans.
Many wore the red, white and blue of the US flag or caps with Mr Trump's iconic 'Make America Great Again' slogan.
Mr Kirk, 31, was shot dead on 10 September while speaking at a Utah university as part of his popular public debate series.
Authorities arrested a suspect after a 33-hour manhunt and prosecutors said they will seek the death penalty.
The killing of the founder of Turning Point USA, a right-wing youth action campaign, has inflamed acrimonious and violent political divisions in the United States.
Authorities say the suspected 22-year-old gunman cited the "hatred" he believed was stoked by Mr Kirk - who was a vitriolic critic of transgender people, Muslims and others.
Mr Kirk used his millions of social media followers, the massive audience of his podcast and appearances at universities to bolster Mr Trump with young voters and fight for a nationalist, Christian-centric political ideology.
Even before the alleged killer was identified or arrested, Mr Trump called Mr Kirk "a martyr for truth and freedom" and blamed the rhetoric of the "radical left".
The US president has lauded Mr Kirk's role in helping him get re-elected in November last year.
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In response to the killing, the White House last week declared it would crack down on what it terms "domestic terrorism" by the political left.
Mr Trump said he would designate "Antifa" - a shorthand term for "anti-fascist" used to describe diffuse far-left groups - as "a major terrorist organisation," a move he threatened in his first term.
Prominent late-night talk show host Jimmy Kimmel was pulled off the air on Wednesday, hours after the government threatened to cancel broadcasting licenses because of comments he made about Mr Kirk's killing.
The moves have sparked alarm among Mr Trump's critics who warn of possible steps to silence dissent of his divisive right-wing White House tenure, marked by a rolling back of social justice policies and an immigration crackdown that has seen widespread complaints of rights abuses.
