US President Donald Trump's response to the Charlottesville attack was "not enough", Labour leader Jeremy Corbyn has said.
After deadly violence erupted over a white supremacist rally in Virginia, Mr Trump said he condemned "hatred, bigotry, and violence on many sides".
Mr Corbyn said that "any president... should be able to condemn" white supremacists.
He rejected comparisons with his own comments about violence in Venezuela.
More than 120 people have died during months of anti-government protests in Venezuela, and Mr Corbyn faced criticism after he condemned violence committed "by any side".
He has been under pressure to condemn the country's President, Nicolas Maduro, having previously expressed support for him and his predecessor, Hugo Chavez.
In Charlottesville, Virginia, a woman was killed on Saturday when a car rammed into a crowd protesting against a far-right rally.
Nineteen people were injured in the car-ramming incident, and another 15 people were wounded in separate clashes related to the march.
President Trump was strongly criticised by Republicans and Democrats after he said he condemned "in the strongest possible terms this egregious display of hatred, bigotry, and violence on many sides".
A White House spokesman said later that his condemnation included white supremacists.
"It's not enough," Mr Corbyn said.
"What happened in Charlottesville was the KKK [Ku Klux Klan] and its supporters, white supremacists, arrived in Charlottesville in order to cause trouble.
"Surely every president of every country in the world... should be able to condemn that."
Last week, Mr Corbyn was asked whether he condemned President Maduro's actions and said: "What I condemn is the violence that's been done by any side, by all sides, in all this."
But on Monday he insisted "there is no equivalence between white supremacists trying to kill somebody in Charlottesville" and the situation in Venezuela.
"Yes, there are problems in Venezuela," he added, "and what I have called for is the same as [French] President Macron has called for: calm, peace, negotiations, and a constitutional way forward."
Asked whether President Trump's response to the Charlottesville rally had been robust enough, Prime Minister Theresa May's spokesman told reporters: "What the president says is a matter for him.
"We are very clear... we condemn racism, hatred and violence. We condemn the far right."