Kanye West met Republican US president-elect Donald Trump to discuss what he said were "multicultural issues" including bullying, education and violence.

West's meeting at Trump Tower fuelled speculation about a possible performance at Trump's inauguration or an informal administration role for the rapper.

But West, 39, said on Twitter he had wanted to meet Trump "to discuss multicultural issues".

"These issues included bullying, supporting teachers, modernising curriculums, and violence in Chicago," tweeted the singer who was raised in Chicago.

"I feel it is important to have a direct line of communication with our future president if we truly want change."

The 15-minute meeting was the first major outing by West since he was released on November 30 after a week in a Los Angeles psychiatric hospital with an unexplained condition.

Asked about the purpose of the 15-minute meeting, Trump told reporters afterward, "Friends, just friends. He's a good man. Long time. Friends for a long time."