President Trump threatened to designate left-wing activist group Antifa as a terrorist organization in a Saturday tweet just hours before the start of opposing demonstrations in Portland, Oregon.

“Major consideration is being given to naming ANTIFA an ‘ORGANIZATION OF TERROR,’” Trump posted. “Portland is being watched very closely. Hopefully the Mayor will be able to properly do his job!”

Members of far-right groups, including the Proud Boys, plan to rally in Portland Saturday.

Masked members of the local Rose City Antifa, billed as “the nation’s oldest active anti-fascist group” and known for its use of violent tactics in street confrontations, say they will battle them.