Story highlights This isn't the first time Romney has spoken out against Charlottesville

Romney has been a strong critic of Trump in the past

Washington (CNN) Mitt Romney called on President Donald Trump Friday to apologize for his comments about Charlottesville, Virginia, saying the President's remarks this week "caused racists to rejoice."

"The potential consequences are severe in the extreme," Romney wrote in a Facebook post . "Accordingly, the president must take remedial action in the extreme. He should address the American people, acknowledge that he was wrong, apologize."

He said that Trump's remarks -- in which he blamed "both sides" for inciting violence, an equivocation between neo-Nazis and those protesting them -- had a hurtful impact on the nation.

"Whether he intended to or not, what he communicated caused racists to rejoice, minorities to weep, and the vast heart of America to mourn," Romney wrote. "His apologists strain to explain that he didn't mean what we heard. But what we heard is now the reality, and unless it is addressed by the president as such, with unprecedented candor and strength, there may commence an unraveling of our national fabric.

Romney also called this a "defining moment" for Trump.