Oregon Governor Kate Brown on Friday declared a state of emergency in Portland this weekend due to the risk of violence that may take place as thousands of members of what she called "white supremacist groups" such as the Proud Boys hold a rally.
Leaders of the self-described "Western chauvinist" Proud Boys called Saturday's rally to "end domestic terrorism" after four months of near daily demonstrations against police violence and racism in Portland.
Many out-of-state demonstrators, some armed, were expected to attend the event.
Proud Boys chairman Enrique Tarrio said his group did not intend to cause violence.
Posting on Twitter: "We will be peaceful unless provoked. I encourage people to protest us."
Civil rights group The Southern Poverty Law Center classifies the Proud Boys as a hate group, citing its members' anti-Muslim and misogynist rhetoric.
The men-only Proud Boys group describes itself as a fraternal organization that is "anti-racism" and "anti-political correctness."
President Donald Trump, who has made law and order a principal theme of his bid for re-election, has singled out Portland as one of several Democratic-led cities he calls "anarchist jurisdictions."
His Democratic challenger, former Vice President Joe Biden, says Trump's rhetoric is stoking the violence.