President Donald Trump said he will designate "Antifa" as a terrorist organization, after vowing to punish groups linked to political violence originating from the left.

President Donald Trump early Thursday said he would designate Antifa as a terrorist organization. Photo by Bonnie Cash/UPI UPI

Sept. 18 (UPI) -- President Donald Trump said he will designate Antifa as a terrorist organization, after vowing to punish groups linked to political violence originating from the left following the shooting death of conservative provocateur Charlie Kirk.

Trump made the statement early Thursday on his Truth Social media platform from Britain where he is on a state visit.

"I am pleased to inform our many U.S.A. Patriots that I'm designating ANTIFA, A SICK, DANGEROUS, RADICAL LEFT DISASTER, AS A MAJOR TERRORIST ORGANIZATION," he said.

"I will also be strongly recommending that those funding ANTIFA be thoroughly investigated in accordance with the highest legal standards and practices."

It was unclear how he would designate Antifa as a terrorist organization, as Antifa is a movement, like Anonymous and Occupy Wall Street, and does not have card-carrying members.

An abbreviation of anti-fascist, the Antifa movement is decentralized and non-hierarchical. Its activists stand against White supremacy, neo-Nazism, racism and other similar ideologies. Though it predates Trump's first term, that was when it large significant growth.

Trump previously threatened to designate Antifa as a terrorist organization in 2019.

Earlier, the Trump administration said the president would use his executive powers to target organizations, including Antifa.

During a press conference in the Oval Office on Monday, Trump said designating Antifa as a terrorist organization "is something I would do" if he had the support of other members of his Cabinet, in particular Attorney General Pam Bondi.

"I would do that 100%, and others also, by the way. But Antifa is terrible," he said.

The announcement comes as the United States is still dealing with the fallout from Kirk's assassination on Sept. 10. Suspect Tyler Robinson, 22, has been charged with Kirk's murder.

Hours after Kirk was killed, Trump released a recorded statement blaming the "radical left" for his ally's death, despite no suspect having yet been caught.

He also vowed to "find each and every one who contributed to this atrocity and to other political violence, including organizations that fund it and support it."