US President Donald Trump succumbed to two days of growing pressure from within his own Republican Party, and condemned racist ideologies and hate groups, naming the KKK, neo-Nazis and white supremacists.

"Racism is evil and those who cause violence in its name 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," Trump said from the White House.

Trump came under criticism on Saturday after he issued a lackluster response to the violence. Rather than explicitly denounce the white nationalist groups for instigating and escalating the violence, Trump told reporters that he condemned the "egregious display of hatred, bigotry and violence, on many sides. On many sides."

Officials were subsequently forced to scramble before the media on Sunday to clarify the president's position. An additional White House statement on Sunday did explicitly denounce the Ku Klux Klan and neo-Nazi groups, although it was attributed to an unnamed spokesperson, rather than to Trump himself.

German Chancellor Angela Merkel's office on Monday condemned white supremacist marches in Charlottesville, Virginia at the weekend as "disgusting."

The chancellery also denounced an attack against counter demonstrators, which left one woman dead, as "evil."

"The scenes at the right-wing extremist march were absolutely repulsive - naked racism, anti-Semitism and hate in their most evil form were on display," Merkel's spokesman Steffen Seibert told reporters. "Such images and chants are disgusting wherever they may be and they are diametrically opposed to the political goals of the chancellor and the entire German government."

Read more: Opinion: Charlottesville violence reflects Trump America

Seibert added that the chancellor stood in solidarity with the counter protestors who peacefully opposed the rallying far-right groups, including the Ku Klux Klan. Merkel also regretted the death of 32-year-old Heather Heyer, who was killed after a car ploughed into a crowd of counter protestors, Seibert said.

Lawmakers decry Trump's frail response

The deputy head for Germany's leading Christian Democrats (CDU) party, Armin Laschet, said he wished that Trump would denounce the racist violence as directly as his Republican predecessor Ronald Reagan had in the 1980s.

Meanwhile, German Justice Minister Heiko Maas - a member of the Social Democrats, the junior coalition partner to Merkel's conservatives - criticized the US president's decision to repeatedly speak of "violence on many sides."

"His half-hearted dithering on the right-wing extremist violence is fatal error," Maas tweeted. "Every democrat must find the right words to stand up against racism. Those who can't demonstrate a definitive stand must reckon with the fact that they are empowering neo-Nazis.

The British government on Monday also issued a similar statement to Trump's lackluster response to the Charlottesville rallies. Asked by reporters whether Trump's response had been robust enough, a spokesman for UK Prime Minister Theresa May said: "What the president says is a matter for him. We are very clear ... We condemn racism, hatred and violence," he said. "We condemn the far right."

bik,dm/rc (AFP, Reuters, KNA, AP)