Music legend Stevie Wonder has launched a stinging attack on President Donald Trump, telling him: "It's a bad day when I can see better than your 2020 vision."

In a five-minute video uploaded to social media, the 'Isn't She Lovely?' singer hit out at Trump for his muted reaction to the Black Lives Matter movement.

"Black lives do matter and this is not another digital viral trend or hashtag, it has to be the beginning of the end of all this bulltish. It is our lives," the 70-year-old told his followers. "Yes all lives do matter, but they only matter when black lives matter too.

"I've heard the person in the highest place of this nation say, 'There are fine people on both sides.' That sounds noncommittal to me."

Wonder then reeled off some of Trump's more outrageous statements, continuing: "'I have a great relationship with the Blacks'. Peaceful protesters called 'thugs,' immigrants called 'rapists.'

"And from the very place that civilisation began, Africa, I've heard this Commander-in-Chief call it an s-h-i-t-hole. Wow. One day, you will surely be sorry."

Prior to the resurgence of the Black Lives Matter movement and the coronavirus crisis, Trump had been considered a shoo-in for a second term as president, but his Democratic challenger Joe Biden is now odds-on favourite to win in the polls this November.