South Africa's second biggest political party launched a legal challenge Monday against a new land expropriation law that was roundly criticized by U.S. President Donald Trump as a rights violation against a white minority and prompted him to cut all funding to the country.

Although the Expropriation Act, which was signed by South African president Cyril Ramaphosa in January, includes safeguards against abuse, Trump proclaimed that “South Africa is confiscating land, and treating certain classes of people VERY BADLY," and vowed to order an investigation by the U.S. government.

The president ordered that all foreign assistance to South Africa be halted and said his administration would prioritize the resettling of white, “Afrikaner refugees” into the United States.