A group known as Patriot Prayer has received approval for a First Amendment permit by the National Parks Service to gather on August 26 at Crissy Field in San Francisco.
"We do not invite hate speech, or hate, to come to our city and to instigate potential violence," said Mayor Ed Lee at a news conference on Tuesday afternoon.
Lee says there is a difference between "free speech and hate speech with intent to cause violence," adding that he believes these groups are, "coming here to commit violence... aiming their guns at our people, and we are going to stop them."
I-TEAM: New breed of white nationalist leadership based in California
The event is one of two scheduled in the Bay Area that weekend. A "No to Marxism in America" rally is planned the following day at Martin Luther King Jr. Civic Center Park in Berkeley. The two-day event is being billed as "Liberty Weekend in the Bay Area."
This comes after a violent right-wing rally last weekend in Charlottesville, Virginia, in which a man allegedly drove a car into a crowd of counter-protesters, killing one woman and injuring 19 other people.
TIMELINE: Charlottesville Virginia protests, rallies, and violence
Mayor Lee, who does not believe the permits issued before Charlottesville, says allowing these groups to hold an event following "what we saw in Charlottesville, Berkeley, Portland and Seattle," needs to be reevaluated.
Mayor Lee says the city has reached out to the National Parks Service asking them to reevaluate the permit and consider input based on safety concerns.
A park service spokeswoman on Monday said the agency is generally required by law to grant all First Amendment permits and is currently working with U.S. Park Police and San Francisco law enforcement to develop plans for security at the event.
"You are not welcome in San Francisco... We will do everything we can to stop this from happening!" Supervisor London Breed— Kate Larsen (@KateABC7) August 15, 2017
"Outraged is an understatement," said London Breed, President of the San Francisco Board of Supervisors and District 5 Supervisor. She says this event promotes "hate, racism, and violence."
"We will stand strong against the National Park Service and the Trump administration," said Breed.
The mayor says he "wants clarity" on what the National Park Service is permitting and under what conditions.
Some of the conditions city leaders want to be considered are what exactly is being permitted and what associated groups may accompany them. They also have concerns over routes to the event, saying trouble can occur after the event in parking lots and along the road, which also needs to be taken into consideration.
Based in Portland, Oregon, Patriot Prayer is an "alt-right" group specializing "in rallies aimed at provoking far-left and anarchist groups," according to the Southern Poverty Law Center, which tracks hate groups. Violence has been documented at other events organized by the group.
The group, organized by Joey Gibson, also held an event in Seattle on Sunday, only a day after the Charlottesville rally.
The Seattle event was greeted by a loud and angry group of counter-protesters, a tense atmosphere, and a heavy police presence, according to published reports. Police deployed pepper spray and worked to keep the two groups separate and the day ended without major violence.
According to their Facebook page, the event begins at 2 p.m. on Saturday in San Francisco, "for a day of freedom, spirituality, unity, peace, and patriotism!"
They go on to write: "San Francisco has long been a city that prides itself in acceptance of all, so together, let's unite in this beautiful city to listen to some great speakers & live music!"
Speakers will include: Joey Gibson of Patriot Prayer, Will Johnson of Unite America First, Harim Uziel of Los Angeles For Trump, Amber Gwen Cummings, a transsexual patriot, activist Gabriel Silva and many more.
RELATED: 'Everyone's hearts are aching': Cities hold vigils in wake of Charlottesville attack
Another group known as No Marxism in America is also planning a rally and that one is expected to take place at Civic Center Park in Berkeley from 1 p.m. to 5 p.m. next Sunday.
National Park Service officials said they are working with city police and fire officials to come up with a safety plan.
Some California politicians raised concerns over the planned event. House Minority Leader Nancy Pelosi said she is concerned over safety issue.
House Minority Leader Nancy Pelosi also called on the National Park Service to reconsider allowing a right-wing rally to go ahead, arguing that the event poses a threat to public safety.
"I am deeply alarmed by the hateful and dangerous nature of the event, its timing so soon after the horrors in Charlottesville, and the serious questions over whether the National Park Service is at all equipped
to ensure public safety during a white supremacist rally," Pelosi said.
"The NPS should reevaluate its decision and its capacity to protect the public during such a toxic rally," she said. "Free speech does not grant the right to yell fire in a crowded theater, incite violence or
endanger the public in any venue."
Bay City News contributed to this report.
Difference between "free speech and hate speech with intent to cause violence" SF Mayor Ed Lee. "People coming here to commit violence."— ABC7 News (@abc7newsbayarea) August 15, 2017
"To say we are outraged is an understatement" Supervisor London Breed re:NPS issuing permit for 8/26 rally at Crissy Field— Kate Larsen (@KateABC7) August 15, 2017
"we do not invite hate speech... and potential violence... into our city..." Mayor asked National Park Service to reevaluate their decision— Kate Larsen (@KateABC7) August 15, 2017
RE:white supremacist rally in SF “We must wonder,where is the decision to permit a white supremacist rally in a national park being made?" pic.twitter.com/XagdL9G3Hh— Kate Larsen (@KateABC7) August 15, 2017