President Cyril Ramaphosa has not yet commented but previously defended South Africa’s land policy after Trump’s threat on Sunday.
He said the government had not confiscated any land and the policy was aimed at ensuring equitable public access to land.
President Ramaphosa’s law was signed last month, and allows land seizures without compensation in certain circumstances.
Land ownership has long been a contentious issue in South Africa with most private farmland owned by white people, 30 years after the end of the racist system of apartheid.
There have been continuous calls for the government to address land reform and deal with the past injustices of racial segregation.
South Africa’s new law allows for expropriation without compensation only in circumstances where it is “just and equitable and in the public interest” to do so.
This includes if the property is not being used and there is no intention to either develop or make money from it, or when it poses a risk to people.
The order said the US “cannot support the government of South Africa’s commission of rights violations in its country”, and as long as it “continues these unjust and immoral practices” then the US will not provide aid or assistance.
The White House said Washington will also formulate a plan to resettle South African farmers and their families as refugees.
It said US officials will take steps to prioritise humanitarian relief, including admission and resettlement through the United States Refugee Admissions Program for Afrikaners in South Africa, who are mostly white descendants of early Dutch and French settlers.
The executive order, external also references South Africa’s role in bringing accusations of genocide against Israel before the International Court of Justice (ICJ).
The order said: “In addition, South Africa has taken aggressive positions towards the United States and its allies, including accusing Israel, not Hamas, of genocide in the ICJ, and reinvigorating its relations with Iran to develop commercial, military, and nuclear arrangements.”
BBC News