The South African government has dismissed accusations by the US that it harassed and intimidated American officials during a raid on a centre processing applications by white South Africans for refugee status in the US.
Tuesday's raid saw seven Kenyans expelled from South Africa for working in the country illegally.
The US accused South Africa of publishing the passport details of its officials, saying this was unacceptable and warning of severe consequences.
But South Africa has denied this, saying it treats matters of data security with the utmost seriousness.
The US is offering asylum status to members of South Africa's Afrikaner community as it says the community is facing persecution. South Africa's government has rejected the claims.
President Donald Trump's administration has reduced its yearly intake of refugees from around the world from 125,000 to 7,500, but says it will prioritise Afrikaners, who are mostly descendants of Dutch and French settlers.
Tensions between the two countries has risen since Trump took office.
After the raid on the processing centre, South Africa expressed concern that foreign officials appeared to have coordinated with undocumented workers and said it had reached out to the US and Kenya to resolve the matter.
In a statement issued on Thursday, the US State Department condemned in the strongest terms the South African government's recent detention of US officials performing their duties to provide humanitarian support to Afrikaners.
It did not providence any evidence to back up its accusation that South Africa had released the passport information of its officials. South Africa's home affairs department described these accusations as unsubstantiated.
Last month, the US boycotted the G20 summit in South Africa and has said it would not invite South African officials to its meetings since it took over the leadership of the grouping of the world's biggest economies.
