US President Donald Trump said Saturday that he condemned racism as the nation marked the anniversary of deadly unrest triggered by a neo-Nazi rally in Charlottesville, Virginia.

"The riots in Charlottesville a year ago resulted in senseless death and division," Trump wrote on Twitter.

"We must come together as a nation. I condemn all types of racism and acts of violence. Peace to ALL Americans!"

Last year's protests began August 11 and saw hundreds of neo-Nazi sympathizers, accompanied by rifle-carrying men, yelling white nationalist slogans while wielding flaming torches in scenes eerily reminiscent of racist rallies held in America's South before the Civil Rights movement.

They had gathered to protest efforts to remove statues of Confederate leaders, including one of the Confederacy's top general, Robert E Lee.

When the demonstrations continued on August 12, fighting broke out between neo-Nazi supporters and anti-fascists from a black-clad group called Antifa.

The violence culminated with a man driving a car into a crowd of counter-protesters, killing a woman and injuring 19 people.

In the immediate aftermath, Trump drew broad criticism when he initially appeared to establish a moral equivalence between the two groups of protesters and refused to criticize the far rightwingers.

He did eventually yield to immense political pressure and condemn white nationalism.

But just a day later, Trump said there was "blame on both sides" for the violence, condemning the anti-fascists who came "with clubs in their hands."

"I think there's blame on both sides," Trump said. "But you also had people that were very fine people, on both sides."