South Africa's apartheid-era President FW de Klerk has been diagnosed with cancer, according to his foundation.

It said the former president was found with "mesothelioma, which is a cancer that affects the tissue that lines the lungs".

Mr De Klerk, the last white man to lead South Africa, turned 85 on Thursday.

The foundation said he will start a course of immunotherapy next week.

"There is no immediate threat and we are confident that the treatment will be successful," the De Klerk foundation said.

Mr De Klerk shared the 1993 Nobel Peace Prize with Nelson Mandela after helping to negotiate an end to apartheid.