US President Donald Trump said Tuesday that both the left and the right contributed to the violence in Charlottesville in Virginia state over the weekend, reiterating controversial comments he initially made in reaction to the protests that left three dead.

"I think there's blame on both sides. I have no doubt about it, and you don't have any doubt about it either," Trump said during a bad-tempered press conference at Trump Tower in New York, during which he argued with journalists who he called "fake news."

"You had a group on one side that was bad, you had a group on the other side that was also very violent, but nobody wants to say that," Trump said.

Trump said the alt-left group were also "charging at the alt-right with clubs." 

"Do they have any problems? I think they do," he said.

Further questioning the leftist groups, who rallied in support of taking down a statue of Confederate general Robert Lee in Charlottesville, Trump said the trend of abolishing memorials of figures associated with slavery was concerning.  

"So this week it's Robert E. Lee. I noticed that Stonewall Jackson's coming down. I wonder, is it George Washington next week? And is it Thomas Jefferson the week after?" he said, adding "where does it stop?"

Trump also defended his initial response to the violence by saying that he was avoiding jumping to conclusions before gathering all the facts.

Trump came under attack Saturday after stating that "many sides" displayed violence in the town which claimed three lives. He clarified on Monday that white supremacists, neo-Nazis and the Ku Klux Klan were among the groups that instigated the violence.  

The president of the main US labor union resigned from Donald Trump's council on manufacturing Tuesday, saying the US president's response to violent white supremacists in Charlottesville meant he tolerated "bigotry and domestic terrorism."

"We cannot sit on a council for a President who tolerates bigotry and domestic terrorism," AFL-CIO president Richard Trumka said in a statement announcing his immediate resignation from the panel. "President Trump's remarks today repudiate his forced remarks yesterday about the KKK and neo-Nazis. We must resign on behalf of America's working people, who reject all notions of legitimacy of these bigoted groups."  

In the meantime, Thea Lee, an economist and former deputy chief of staff at the AFL-CIO, also resigned from the council.

Trumka and Lee became the fifth and sixth members to leave the panel, in a move responding to Trump’s failure to immediately condemn far-right groups demonstrating in Charlottesville over the weekend.