RAPPER Kanye West has described slavery as a choice, praised Donald Trump for doing "the impossible" by becoming US president and attributed his 2016 mental breakdown to opioid addiction.

In the latest in a series of startling interviews, tweets and videos, West, 40, also revealed he had undergone liposuction some years ago because he did not want to be called fat.

The Grammy Award-winning musician's most controversial comments came in a rambling video interview at the Southern California offices of celebrity website TMZ.com where he was asked about his recent Twitter spree.

West emerged from a year's silence on Twitter two weeks ago to post up to 20 tweets an hour on topics ranging from politics, philosophy and fashion to his own image. He also said he had fired his manager.

At one point in the TMZ interview, shown on its website, West says, "When you hear about slavery for 400 years. For 400 years? That sounds like a choice."

The civil rights group NAACP said in a Twitter response addressed to West, "There is a lot of misinformation out there and we are happy to provide insight. Black people have fought against slavery since we first landed on this continent."

On Tuesday, the "Jesus Walks" singer also gave the first details of his November 2016 admission to a Los Angeles psychiatric hospital after a series of curtailed concerts and political rants.

"I was drugged out," he said in the TMZ interview. "Two days before I was taken to the hospital I was on opioids. I was addicted to opioids."

He said he was given painkillers after undergoing previously unreported liposuction surgery, adding, "I got liposuction, because I didn't want you' all to call me fat."

In separate video released on Tuesday to match his new single "Ye vs. the People," West discusses the support he voiced for Trump last week, which caused controversy among many of his fans.

Asked what he admired about Trump, West told fellow rapper T.I., "the ability to do what no one said you can do, to do the impossible."

In the single, West raps lines like "Make America Great Again had a negative perception/I took it, wore it, rocked it, gave it a new direction."