WASHINGTON, Sept 16, 2025 (BSS/AFP) - Senior White House official Stephen Miller vowed Monday that the Trump administration would dismantle an alleged "vast domestic terror movement" that he linked to the killing of right-wing activist Charlie Kirk.

Miller, the White House deputy chief of staff, made the comments on Kirk's podcast, which Vice President JD Vance hosted on Monday.

"We are going to channel all of the anger that we have over the organized campaign that led to this assassination, to uproot and dismantle these terrorist networks," said Miller.

Miller and Vance both alleged the existence of a rising left-wing extremist movement, which they said the administration would now target.

"We are going to use every resource we have at the Department of Justice, Homeland Security and throughout this government to identify, disrupt, dismantle and destroy these networks and make America safe again for the American people," said Miller.

The remarks, which come before all details of Kirk's killing are fully known, have sparked alarm among some Trump critics that such a campaign could be used to quash dissent.

While Kirk was a vocal conservative, the United States has seen violence targeting members of both political parties in recent years, amid a sharp rise in polarization and easy access to firearms.

US President Donald Trump escaped two assassination attempts on the campaign trail last year, while a Minnesota Democratic lawmaker and her husband were shot dead by a masked gunman in June.

Two months earlier, a man attacked the home of Pennsylvania Governor Josh Shapiro, a prominent Democrat.

Kirk, a close ally of Trump, was shot Wednesday during a speaking event on a Utah university campus. He was the founder of the influential conservative youth political group Turning Point USA.

On the podcast Monday, Vance was full of praise for a man he called "the smartest political operative I ever met."

"He was a critical part of getting Donald Trump elected as president, getting me elected as vice president," he said.

Trump will attend a memorial service for Kirk on Sunday at a stadium in Arizona.

On Monday, the president said he was considering designating "Antifa" a domestic terrorist organization and bringing organized crime charges against those raising funds for alleged "agitation."

Antifa -- short for "anti-fascist" -- is an umbrella term for diffuse far-left groups, and is often mentioned in right-wing talking points around violence at protests.

Trump has previously threatened to name Antifa a "domestic terrorist organization" in his first term, but never followed through.

While federal law enforcement includes combating domestic terrorism under its purview, the United States does not have a list of designated "domestic terrorist organizations."

- DNA evidence -

Earlier Monday, FBI Director Kash Patel said that DNA found at the scene of the murder had been matched to suspect Tyler Robinson, who was arrested Thursday after a 33-hour manhunt.

The 22-year-old is expected to be formally charged in the murder on Tuesday.

Authorities said the suspect used a rifle to shoot Kirk with a single bullet to the neck from a rooftop.

Patel also discussed a note that Robinson is believed to have written before the crime and later destroyed.

The note is "basically saying... 'I have the opportunity to take out Charlie Kirk, and I'm going to take it,'" Patel said on Fox News.

Kirk, a father of two, used his audiences on TikTok, Instagram and YouTube to build support for conservative talking points, including strong criticism of the transgender rights movement.

A polarizing figure, he often posted carefully edited clips of his interactions during debates at his many college events.

Utah Governor Spencer Cox on Sunday said Robinson was romantically involved with a transgender roommate and had "leftist ideology."

Patel has been heavily criticized for his actions in the immediate aftermath of the shooting, including having quickly announced the arrest of a suspect, only to confirm they had been released two hours later.

On Monday, Patel defended his actions.

"Could I have worded it a little better in the heat of the moment? Sure. But do I regret putting it out? Absolutely not," he said.

Patel is expected at Congress on Tuesday to answer questions from lawmakers.