President Cyril Ramaphosa has called a group of 59 white South Africans who have moved to the US to resettle "cowards", saying "they'll be back soon".

The group of Afrikaners arrived in the US on Monday after President Donald Trump granted them refugee status, saying they faced racial discrimination.

But Ramaphosa said those who wanted to leave were not happy with efforts to address the inequities of the apartheid past, terming their relocation a "sad moment for them".

"As South Africans, we are resilient. We don't run away from our problems. We must stay here and solve our problems. When you run away you are a coward, and that's a real cowardly act," he added.

Trump and his close ally, South Africa-born Elon Musk, have said there was a "genocide" of white farmers in South Africa - a claim that has been widely discredited.

The US has also accused the South African government of seizing land from white farmers without paying compensation.

More than 30 years after the end of decades of rule by South Africa's white minority, black farmers own only a small fraction of the country's best farmland, with the majority still in white hands, leading to anger over the slow pace of change.

In January President Ramaphosa signed a controversial law allowing the government to seize privately owned land without compensation in certain circumstances, when it is deemed "equitable and in the public interest".

But the government says no land has yet been seized under the act.

Trump has offered to resettle the white Afrikaners, descendants of mostly Dutch settlers, saying they were fleeing a "terrible situation" in South Africa.

Speaking on Monday at an agricultural exhibition in the Free State province, Ramaphosa said the Afrikaners were moving to the US because they were not "favourably disposed" to efforts aimed at addressing the country's challenges.

"If you look at all national groups in our country, black and white, they've stayed in this country because it's our country and we must not run away from our problems. We must stay here and solve our problems," Ramaphosa said.

"I can bet you that they will be back soon because there is no country like South Africa," he added.

His "coward" remark angered some social media users, who condemned it as an insult to aggrieved white South Africans.

The group of Afrikaners were welcomed by top US officials who claimed they had been "living under a shadow of violence and terror" in South Africa.

"Welcome to the land of the free," Deputy Secretary of State Chris Landau said as he received the South Africans who landed at Dulles airport near Washington DC on Monday.

Some held young children and waved small American flags in the arrival area adorned with red, white and blue balloons on the walls.

Earlier on Monday, President Ramaphosa told an Africa CEO forum in Abidjan, Ivory Coast, that he had recently told Trump during a phone call the US assessment of the situation was "not true".

"We're the only country on the continent where the colonisers came to stay and we have never driven them out of our country," he added, dismissing claims Afrikaners were being persecuted.

Ramaphosa said dozens of white South Africans who arrived in the US on Monday "don't fit the bill" for refugees.

According to the US embassy in South Africa, to be considered eligible for the refugee resettlement scheme, someone must be:

• Of South African nationality
• Afrikaner or from a racial minority
• Able to cite an incident of past persecution or fear of persecution in the future.

The South African leader said he was due to meet his US counterpart soon regarding the issue.

Trump has threatened to boycott the forthcoming G20 summit in South Africa unless the "situation is taken care of".