South Africa's President Cyril Ramaphosa has given an assurance that his government is not "sleeping on the job" as the country experiences crippling power cuts.

Answering questions in parliament, Mr Ramaphosa said three ministers were working to resolve the crisis, including restructuring the state-owned power company, Eskom.

"We are not sleeping on the job and we are hoping that all these efforts will lead to a solution that the people of South Africa want to see," he said.

Many households and businesses have to go without power for more than 10 hours a day, in the worst electricity crisis to hit South Africa.

The power crisis has also affected the currency market - the South African rand hit a three-year low against the US dollar on Thursday.