Rapper Nas has written an open letter to Donald Trump and his administration, criticizing the president for his treatment of minorities and people of color.

The 43-year-old musician, writing for the website Mass Appeal, took aim at the president for failing to use the power of his office to try to mend the country’s racial tensions.

“We all know a racist is in office,” Nas wrote. “People can talk their shit. Comedians can sound racist. People can go through their moments of that shit, but when you have the responsibility of being president and you carry on like that, you send a strong message to people outside of your group that they ain’t worth shit.”

He went on to address the importance of artistic expression in politically fraught times, imploring readers to run for office and take action. “It’s the same way I felt as a youngster when Ronald Reagan was in office. My voice at that point didn’t fuckin’ matter to anybody. I didn’t care.”

Since the 1994 release of Illmatic, Nas has never shied away from addressing institutionalized racism – both in his music and public statements. Late last year, he raised money for criminal justice reform by selling “ugly” Christmas sweaters with a kneeling Santa, an allusion to Colin Kaepernick’s national anthem protest. And in a verse on Robin Thicke’s 2016 single Deep, he wrote: “A toupee-wearin’ liar’s tryna run the USA.”

In the letter Nas stressed that, regardless of who’s in office, he’ll continue to make music, as others should. And on Tuesday he and Lauryn Hill – who’s also been a vocal supporter of Black Lives Matter, releasing a song called Black Rage in the wake of Michael Brown’s shooting – announced a joint North American tour, kicking off on 7 September in Chicago.

“But in reality, art is gonna thrive regardless,” Nas continued in the letter. “Whether it’s affected by who’s in office or not, art thrives. I live in that – I live in those walls, I live in those wires, I live in those pencils and papers, and that sound. I’m not caught up in politics. I saw Gerald Ford and his vice president Nelson Rockefeller. I saw Jimmy Carter. I saw Ronald Reagan, and I saw George Bush Sr. I saw Bill Clinton, George Bush, and Barack Obama. I’m good.”

Tickets for Nas and Lauryn Hill’s 17-city tour go on sale on 2 June.