Mounting criticism: Iran supreme leader mocks US over Charlottesville

Ayatollah Ali Khamenei said "if US has any power, they better manage their country, tackle #WhiteSupremacy rather than meddle in nations' affairs. #Charlottesville," in a tweet published on the official Twitter account.

The tweet was in reference to the furore in the US over an attack in Charlottesville by a suspected Nazi sympathiser who ploughed his car into anti-racism protesters, leaving one dead and 19 injured.

US President Donald Trump triggered outrage when he responded to the attack by suggesting there was “blame on both sides”, despite the alt-right protesters making their white supremacist views public.

In comments that were warmly embraced by David Duke, a former "grand wizard" of the Ku Klux Klan, Trump on Tuesday said the "alt-left" was partly responsible for the deadly violence in Charlottesville, and said there were "very fine people on both sides" of the protest.

Trump's remarks - made at an impromptu press conference that was expected to focus on infrastructure reforms - put the white supremacists and counter-demonstrators on equal moral ground.

"What about the alt-left that came charging... at the, as you say, the alt-right? Do they have any semblance of guilt? (...) There are two sides to a story."

Trump had suffered a first wave of indignation immediately after Saturday's events, when critics said his comments were too vague and did not go far enough to denounce neo-Nazis and KKK members at the Charlottesville rally.

Obama, his predecessor, had reacted by tweeting a quote from Nelson Mandela: "No one is born hating another person because of the color of his skin or his background or his religion."

The tweet is now the most "liked" ever sent on the social network, Twitter said Wednesday.

In an editorial, The New York Times said Trump's behavior "has become distressingly unsurprising."

"Washington politicians had hoped the recent appointment of John Kelly, a retired Marine general, as his chief of staff would instill some discipline in his chaotic administration," the paper said.

"But the root of the problem is not the personnel; it is the man at the top."