Rapper Nicki Minaj is under pressure from human rights activists who are calling for the rapper to cancel her upcoming performance in Angola, due to the controversial leadership of the country's president.

The Superbass star is slated to headline Show Unitel Boas Festas, a Christmas festival scheduled for Saturday (19Dec15) in Luanda, the capital of the African country.

However, the head of the Human Rights Foundation, Thor Halvorssen, has penned an open letter to Minaj, asking her to scrap her planned gig over continuing allegations President Jose Eduardo dos Santos often uses his power to violate the basic rights of journalists, activists and others who speak out against government oppression.

"Beyond censoring through violence, the Angolan regime owns the only national radio station, controls the only daily newspaper, and exerts control over Angola’s television stations," Halvorssen writes. "Artists such as yourself are not allowed to freely express their opinions in Angola, where criticizing the government is a crime punishable with fines and imprisonment."

He notes the ongoing controversy of Angolan hip-hop artist Luaty Beirao, who was arrested in June (15) after attending a meeting to discuss democracy and non-violence in the country. There is currently a trial underway against him and 16 others who took part in the event.

"Millions of people look up to you for creative inspiration," Halvorssen writes. "You have no good reason... to do business with the corrupt Angolan dictatorship and endorse the ruler’s family company... 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 also praises the rapper's ongoing philanthropic efforts, particularly with young people and education, but points out dos Santos and his cabinet are preventing kids from getting a solid education. He writes, "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. What kind of inspirational message are you sending to millions of young Angolans by performing for the dictatorship that has literally stolen their freedom and their future?"

A representative for Minaj has yet to comment on the letter.

Halvorssen has been outspoken against celebrities who seem to support controversial leaders around the world, previously criticizing the likes of feminist icon Gloria Steinem for conduction a peace conference in North Korea with the dictator's support, actress Hilary Swank who accepted money to attend the birthday party of Chechen president Ramzen Kadyrov and Jennifer Lopez, who allegedly accepted $1.5 million from authoritarian Turkmenistan President Gurbanguly Berdimuhamedov for performing at his birthday bash.