Right-wing protesters pepper spray an anti-police protester during a rally in Portland on August 22.File photo: AFP

Governor of US state of Oregon Kate Brown on Wednesday extended her executive order to create a joint incident command structure for public safety to keep peace and protect free speech in Portland as the country continues to wait for national election results.

The order, which had been set to expire at 5:00 pm Wednesday, has been extended until at 5:00 p.m Friday, unless earlier rescinded or extended, the announcement said.

Brown on Monday announced a law enforcement plan to prevent election-related violence and intimidation through Wednesday, in the city of Portland.

Brown has also directed the Oregon National Guard to place its members trained in crowd control on standby in the event they are needed to support law enforcement efforts.

"Across the United States, elections officials are working hard to ensure that every vote is counted, and it may be several days until we know the results of this election," said Brown. "It's important to trust the process, and the system that has ensured free and fair elections in this country through the decades, even in times of great crisis."

"All Oregonians have the right to free expression and peaceful assembly. But political violence, intimidation, and property destruction will not be tolerated," she noted.