A senior figure from South Africa's ruling ANC party has defended his country's sovereignty amid growing tensions with the US over race relations and a new land law.

"We are a free country, we're a sovereign country. We're not a province of the United States and that sovereignty will be defended," ANC National Chair Gwede Mantashe said on Sunday.

US President Donald Trump has hit out at South Africa's new expropriation law, signing an executive order in February stating it was a means by which the government could "seize ethnic minority Afrikaners' agricultural property without compensation".

President Cyril Ramaphosa says the law ensures "public access to land in an equitable and just manner".

The expropriation law does allow the government to seize land without compensation, but only in certain circumstances.

Trump's February order also opened the door for Afrikaaners to be admitted to the US as refugees, describing them as "victims of unjust racial discrimination".

But standing in for Ramaphosa in a speech at South Africa's Freedom Day celebration in the eastern province of Mpumalanga, Mantashe criticised South African citizens who have called on Trump to "punish" the country.

"Now they are told to go there and be refugees, they are refusing. They must go," he said.

Tensions have also played out publicly on Elon Musk's X page, where he has described his country's ownership laws as "racist".

Currently, white South Africans, who are a minority of the population, own most of the country's private land and wealth, despite the racist system of apartheid ending decades ago.

In an effort to quell tensions that have rumbled on for months, South Africa appointed a special envoy to Washington earlier this month.

Mcebisi Jonas will be tasked with advancing the country's "diplomatic, trade and bilateral priorities," Ramaphosa said.

The move comes after Washington expelled South Africa's ambassador, Ebrahim Rasool, after he accused Trump of "dog whistle" politics.