Barack Obama has just written the most liked tweet in history.

With one tweet, former US President Barack Obama said what Donald Trump failed to say in the days since a rally of white nationalists and neo-Nazis resulted in the death of a protester in Charlottesville, Virginia.

Now, his August 12 tweet – his first post in almost a month – has become the most-liked tweet in Twitter’s history.

The former President quoted Nelson Mandela in response to the deadly violence that occurred over the weekend.

“No one is born hating another person because of the color of his skin or his background or his religion…” pic.twitter.com/InZ58zkoAm

— Barack Obama (@BarackObama) August 13, 2017

“People must learn to hate, and if they can learn to hate, they can be taught to love…”

— Barack Obama (@BarackObama) August 13, 2017

“…For love comes more naturally to the human heart than its opposite.” – Nelson Mandela

— Barack Obama (@BarackObama) August 13, 2017

His first tweet has amassed more than 3 million likes, with the three-post series being liked by 5.7 million users.

Since leaving office, Obama hasn’t shied away from commenting on major world events and political controversies. He’s tweeted about terrorist attacks, including those in Manchester and London, and John McCain’s brain cancer diagnosis.

Trump finally bowed to pressure to call out white supremacist groups after 32-year-old paralegal Heather Heyer was killed when a man ploughed his car into a group of counter-protesters in Charlottesville on Saturday.

Speaking from the Diplomatic Room at the White House on Monday, Trump said that hatred and bigotry "has no place in America".

"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.

But just yesterday, Trump did an excruciating 360 on his comments, saying that "not all the fact" were known about the aftermath of the rally and that both the left and right-wing sides had "used force".

LISTEN: Mia Freedman and Amelia Lester talk US politics on Tell Me It's Going To Be Okay.

- With AAP.