President Trump issued a stern message to white nationalist groups who rallied in Charlottesville, Va., calling them out by name and vowing justice will be served to those who "acted criminally" over the weekend.

"Racism is evil and those who cause violence in its names are criminals and thugs, including the KKK, neo-Nazis, white supremacists and other hate groups that are repugnant to everything we hold dear as Americans," the president said during an impromptu press conference Monday. "We are a nation founded on the truth that all of us are created equal. We are equal in the eyes of our creator. We are equal under the law, and we are equal under our Constitution. Those who spread violence in the name of bigotry strike at the very core of America."

"To anyone who acted criminally in this weekend's racist violence, you will be held fully accountable. Justice will be delivered," Trump continued.

Trump's remarks came two days after he was criticized by both Republicans and Democrats for not naming white supremacists specifically in his remarks after the Saturday attack.

Violence broke out between white nationalists who gathered in Charlottesville to protest the removal of a statue of Robert E. Lee and counter-demonstrators Saturday.

One woman, Heather Heyer, was killed and another 19 were injured when a 20-year-old man plowed his car into the group of people protesting the white nationalists. The man, identified as James Alex Fields, was arrested and charged with second-degree murder.

Two Virginia State Police officers, Lt. H. Jay Cullen and Berke M.M. Bates, also died when their helicopter crashed when they were responding to the events in Charlottesville.

"These three fallen Americans embody the goodness and decency of our nation," Trump said of the three who died. "In times such as these, America has always shown its true character — responding to hate with love, division with unity and violence with an unwavering resolve for justice."

"No matter the color of our skin, we all live under the same laws. We all salute the same great flag, and we are all made by the same almighty God," the president continued. "We must love each other, show affection for each other and unite together in condemnation of hated, bigotry and violence. We must rediscover the bonds of love and loyalty that bring us together as Americans."

Trump made initial statements about the events in Charlottesville from his golf club in Bedminster, N.J., on Saturday and condemned "this egregious display of hated, bigotry and violence, on many sides."

The president returned to Washington, D.C., on Monday for a series of meetings, including one with Attorney General Jeff Sessions and FBI Director Christopher Wray, which occurred before Trump's remarks. He added in those meetings on Monday morning, as criticism of his Saturday statement grew.

The Justice Department has opened a civil rights investigation into the car attack.