The petition was started Thursday, and by Saturday, had garnered over 35,000 signatures.
The White House is obliged to review the initiative if it reaches the benchmark of 100,000 signees by September 16 – within the 30 day period.
The author of the petition said ant-fascists should be recognized as terrorists because of their “violent actions in multiple cities and their influence in the killings of multiple police officers throughout the United States.”
He added that “terrorism is defined as the use of violence and intimidation in pursuit of political aims,” and urged the Pentagon to be “consistent in its actions.”
“Just as they rightfully declared ISIS a terror group, they must declare Antifa a terror group – on the grounds of principle, integrity, morality, and safety,”the wording of the petition said.
Antifa or the extreme left is known for its violent rivalry with white supremacists and other far-right groups across America.
Last Saturday saw violent clashes between a Unite the Right rally and an Antifa counter-protest in Charlottesville, Virginia.
The violence culminated in a right-wing a activist plowing his car through the crowd, killing one person and injuring 19 others.
President Trump came under fire following the Charlottesville events, as he initially stopped short of condemning the white supremacists and instead placed blame on ”all sides.”
“What about the alt-left that came charging at, as you say, at the alt-right? Do they have any assemblage of guilt?” the US leader said.
“What about the fact that they came charging with clubs in their hands swinging clubs? Do they have any problem? I think they do. That was a horrible, horrible day,” Trump added.
Hundreds of right-wing demonstrators and thousands of left-winger counter-protesters flocked to a park in downtown Boston Saturday for simultaneous rallies.
Security has been boosted, with backpacks, sticks and any other items that can be used as weapons banned.
Before the rally, the Boston Antifa branch has called on its members and supporters to “confront fascism” at Saturday’s rally.
“We’ll see who really, really has the guts at this rally,” the group said in an online video, WCVB reported.
In January, a petition to class the Black Lives Matter movement as terrorist organization was launched. However, it failed to reach the required benchmark, collecting less than 1,000 signatures in a month.
Antifa opponents welcomed the petition on social media, urging followers to sign it as well.
Some users expressed belief that with Trump in office, the initiative had a real chance of passing.