Charlie Kirk's final text to Homeland Security Secretary before he died revealed

It's been a week since right-wing activist Charlie Kirk was assassinated during a Republican rally in Utah, and still, details surrounding his death are continuing to emerge.

Today (16 Sept), it has been revealed that the 31-year-old sent a message to Kristi Noem, the Secretary of Homeland Security, voicing his concerns about the increasing number of high-profile Americans standing up against Donald Trump's immigration policies.

The text was reportedly sent just one day before he was fatally shot.

At the time of his death, Kirk was answering ethical and political questions from attendees, of which there were believed to be over 3,000.

In the midst of a response about the existence of gun violence in America, however, an armed gunman believed to have been hiding on the roof of a college campus building fired a single shot through his neck.

Kirk was killed last week by 22-year-old Tyler Robinson (Trent Nelson/The Salt Lake Tribune/Getty Images)

Though Kirk was later transferred to hospital, his political ally Trump later went on to confirm that he'd died.

Details surrounding the minutes, hours, days and weeks prior to the right-wing activist's assassination have since been coming to light - including one of his final texts.

Appearing on the latest episode of the Pod Force One podcast, Noem herself has since shed light on what would be one of Kirk's final pleas, which he wrote to her in a text message.

The secretary began by telling columnist and co-host Miranda Devine that she hadn't seen the father-of-two's message until Trump had confirmed that he'd died of his injuries.

"Charlie, he was incredible. It still makes me so sad that it’s hard to talk about," Noem, the former South Dakota governor, said.

"The last message he had texted me was the day before he passed away, and it said, 'We have to hold these mayors and local officials accountable for what they’re doing'."

Noem claimed the conservative had sent her a message the day prior to his death (Kevin Dietsch/Getty Images)

She continued: "I think he was watching across this country as people were continuing to be victimised by illegal, criminal activity, and he wanted someone to be held accountable."

Speaking of his murder in general, Noem went on to reveal how the incident has affected her.

"I don’t know why it feels like such a heavy grief, but I think everybody’s feeling that."

22-year-old Tyler Robinson was subsequently arrested and charged over Kirk's murder, as well as felony discharge of a firearm, and obstruction of justice.

He appeared in court yesterday, where Utah County Attorney Jeff Gray said that prosecutors will seek the death penalty.