'Anytime that you commit an attack against people to incite fear, it is terrorism,' says H.R. McMaster

The suspect in a fatal car attack on a group of people protesting a white nationalist rally, may have been involved in domestic terrorism, President Donald Trump's national security advisor suggested Sunday.

"Anytime that you commit an attack against people to incite fear, it is terrorism, it meets the definition of terrorism," H.R. McMaster told ABC News.

"What you see here, is you see someone who is a criminal, who is committing a criminal act, against fellow Americans, a criminal act that may have been motivated by, and we'll see what's turned up in this investigation, by this hatred and bigotry," he added.

James Alex Fields Jr., 20, was identified as the driver of the silver Dodge Charger that plowed into a crowd in Charlottesville, Virginia, Saturday. Heather Heyer, a paralegal, walking with counter protestors was killed in the crash and nearly 20 others were injured.

Fields Jr. was photographed on the front line with other white men holding a shield emblazoned with the black and white emblem of one of the hate groups that participated in the Friday to Saturday white supremacist rally.

The group, Vanguard America, has denied Fields is a member.

The Anti-Defamation League (ADL) describes Vanguard America as "a white supremacist group that opposes multiculturalism and believes America is an exclusively white nation".

Vanguard America uses the Nazi slogan "blood and soil" to romanticize the connection between whites and America, according to the ADL. Blood and soil was chanted by hundreds of white nationalists Friday night carrying lit tiki torches through Charlottsville.

The slogan was also prominent in white supremacist gatherings Saturday.

Trump has faced a range of criticism for his failure to explicitly condemn the white nationalists, who violently clashed with counter-protesters during the two-day rally in Virginia. His silence is contrary to his insistence on explicitly referring to terrorist acts carried out by Muslims as "radical Islamic terrorism".

"He didn’t call out the white supremacists responsible for the violence," ABC News' George Stephanopoulos said. "When it comes to radical Islamic terrorism, the president said you can’t solve the problem if you don’t say the name. Doesn’t that hold true for domestic terrorism as well?"

McMaster responded by saying Trump "called out anyone, anyone who is responsible for fomenting this kind of bigotry, hatred, racism, and violence" in his condemnation Saturday.

"I think the president was very clear on that," he said.

Trump adviser: any attack to cause fear 'is terrorism'