The president said “consideration” was being given to declaring the movement, which is composed of autonomous left wing groups and individuals in the US, a “major organisation of terror”.
The announcement followed a resolution proposed by senators Ted Cruz and Bill Cassidy earlier this month that condemned the movement and called for its designation as a domestic terrorist organisation.
While it is unclear how seriously Mr Trump is considering the idea, he appeared to be supportive of the move and said it “would make it easier for police to do their job.”
“Consideration is being given to declaring ANTIFA, the gutless Radical Left Wack Jobs who go around hitting (only non-fighters) people over the heads with baseball bats,” he wrote on Twitter on Saturday.
Antifa is known for its use of direct action, which can include property damage, physical violence and harassment against those they view as fascist, and members of the movement have often clashed with Trump supporters.
Although some conservatives have called for Antifa to be stopped, the threat posed by the movement is disputed.
A report by the Anti-Defamation League (ADL) found that extremist-related murders in 2018 were “overwhelmingly linked to right-wing extremists”.
The ADL said it recorded zero killings in 2018 related to left wing extremism and found that “left wing extremists have not been particularly violent over the past 20 years”, with the majority of violence related to property damage.
Hina Shamsi, director of the national security project at the American Civil Liberties Union, told The Washington Post this week that she opposed labelling the group as domestic terrorists.
“It is dangerous and overly broad to use labels that are disconnected [from] actual individual conduct,” she said.
Mr Cruz has said Antifa is an organisation “composed of hateful, intolerant radicals who pursue their extreme agenda through aggressive violence.”
He added: “Time and time again their actions have demonstrated that their central purpose is to inflict harm on those who oppose their views."
Mr Ngo was beaten by protesters who were opposing a march held by the Proud Boys, a far-right group.
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