The United States' top general condemned "racism and bigotry" on Thursday, joining other military leaders in their denunciation of deadly violence in Charlottesville.

The military usually stays out of the political fray, but it has been keen to distance itself from the weekend's neo-Nazi demonstrations because some demonstrators were sporting US military clothes or insignia.

"I can absolutely and unambiguously tell you that there's no place for racism and bigotry in the US military or in the United States as a whole," General Joe Dunford, the chairman of the US joint chiefs of staff, told reporters during a visit to Beijing.

He added that military leaders "were speaking directly to the force and to the American people... to make it clear that that kind of racism and bigotry is not going to stand inside the force... and to remind (the American people) of the values for which we stand in the US military which are reflective of what I believe to be the values of the United States."

The statement contrasts with remarks from President Donald Trump, who said there was "blame on both sides" after a white supremacist rally ended with a suspected Nazi sympathiser ploughing his car into a crowd of counterprotesters, leaving one woman dead and 19 others injured.

"What about the alt-left that came charging... at the, as you say, the alt-right?" the president asked on Tuesday. "Do they have any semblance of guilt?"

The heads of the Army, Navy and Air Force, as well as Pentagon chief Jim Mattis, have responded to the incident in recent days.

Admiral John Richardson, who leads the Navy, called the events in Charlottesville "shameful."

"The Navy will forever stand against intolerance and hatred," he said in a statement Saturday.