President Donald Trump led thousands of his supporters at a mass memorial event Sunday for slain right-wing activist Charlie Kirk, with language highlighting religious fervor.

"He's a martyr now for American freedom," Trump said of Kirk, who was killed on Sept. 10 at a Utah university campus.

Trump was the final speaker to address nearly 65,000 people at the event, held at a stadium in the southwestern U.S. state of Arizona, with people coming from far and wide to pay their respects.

"I look at him as a Christ martyr, definitely," said Monica Mirelez, a 44-year-old nurse who drove more than 12 hours from Texas to attend Kirk's memorial.

Mirelez told AFP she watched Kirk's videos on Instagram every day.