Nicki Minaj is set to headline the Unitel Christmas Festival this Saturday (Dec. 19) in Luanda, the capitol of Angola. But this performance is facing major criticism from Thor Halvorssen, head of the Human Rights Foundation. Halvorseen wants Minaj to cancel the performance because of Angola's long history of human rights violations under President Jose Eduardo dos Santos, who has been in power since 1979.

A copy of the letter Halvorseen sent to Minaj was obtained by The Hollywood Reporter. A few excerpts were released including one where Halvorseen tells the story of Angola rapper Luaty Beirao, who was arrested in June after attending a meeting on democracy and non-violence. A trial against him and 16 others who attended the meeting is currently underway.

"As a strong-willed independent artist, shouldn't you be advocating for the release of the imprisoned rapper Luaty Beirao rather than entertaining the dictator and his thieving family?" Halvorssen wrote.

Halvorseen also made a plea for Minaj to cancel her show and let her know what performing for the president would mean.

"Ms. Minaj, you are well known for being involved with charities such as the Get Schooled Foundation, which helps motivate young people to graduate from high school and succeed in college," Halvorssen wrote. "If you move forward with this performance for the dictator and his family, you will be in league with the people stealing educational resources and opportunity from young Angolans."

See Best Rap Performance Nominees & Winners at the Grammys Over the Years

More From XXL