Combo photo shows Stevie Wonder and US President Donald Trump.

Legendary musician Stevie Wonder has called out US President Donald Trump, in a video for the Black Lives Matter movement. He says its a bad day "when I can see better than your 2020 vision".

In his video, he urged his fans to keep the momentum of the movement going, reports a section of the media.

"It's a bad day when I can see better than your 2020 vision," the visually impaired singer-songwriter quipped in the five-minute video message.

He called out North Dakota, South Dakota and Hawaii for being the only three states to not officially recognise Juneteenth, the day slavery ended in America.

"How did it feel to celebrate freedom that we're still fighting for? Hm, it felt and feels too familiar. I know that dance, I've heard those songs," Wonder recalled about the struggle to officially put Martin Luther King, Jr.'s birthday on the American calendar.

Wonder also recited the chorus of his 1973 classic song "Visions", where he envisions a milk and honey paradise where love trumps hate.

The 70-year-old later encouraged his fans to "move your feet to the polls and move your hands to vote" during the 2020 presidential election this November.

"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 said about Trump without referring to him by name.

"'I have a great relationship with the Blacks'. Peaceful protesters called 'thugs', immigrants called 'rapists'. And from the very place that civilization began, Africa, I've heard this Commander-in-Chief call it an s*****le. Wow. One day, you will surely be sorry."