South Africa's President Cyril Ramaphosa has appointed Roelf Meyer, who served in the last government of the apartheid era, as his new ambassador to the US, his office has said.

The country has not had a top envoy in the US since Ebrahim Rasool was expelled last year after he accused President Donald Trump of trying to "project white victimhood as a dog whistle".

This worsened already strained relations between the nations, which took a downward spiral after Trump's return to office last year.

Ramaphosa's spokesperson Vincent Magwenya confirmed Meyer's appointment to the BBC, saying it would be "immediate".

"I can confirm that President Cyril Ramaphosa has appointed Meyer as South Africa's ambassador to the US," he said.

Meyer, 78, played a key role as one of the chief mediators, alongside Ramaphosa, during the talks to end the racist system of white-minority rule known as apartheid in South Africa in the 1990s.

He was the chief representative of the National Party (NP), which introduced apartheid, while Ramaphosa represented the African National Congress led by Nelson Mandela.

Meyer was constitutional affairs minister in the last NP government and went on to join the government of national unity formed in 1994 when Mandela became president.