South Africa's last apartheid president FW de Klerk will be hospitalised to receive a pacemaker on Tuesday, his spokesman said, as his fellow Nobel peace laureate Nelson Mandela lies critically ill.
De Klerk cut short a visit to Europe over the weekend because of Mandela's ailing health, only to fall ill himself.
"He will be going to hospital today (Tuesday) to have a pacemaker installed," he spokesman Dave Steward told AFP.
"It's a routine procedure. He will spend the night in hospital," he added.
The 77-year-old felt dizzy after his return from Europe on Sunday and saw his physician.
"The specialist recommended immediate installation of a pacemaker," said Steward.
He will receive the device, which helps the heart beat at a normal rate, in a Cape Town hospital.
On the other side of the country 94-year-old Nelson Mandela undergoes a 25th day of treatment in a Pretoria health facility for a recurring lung infection.
He is in a critical but stable condition, the South African president's office said on Monday evening.
De Klerk - a one-time hard-liner - dismantled white-minority rule and authorised the release of Mandela from prison in 1990, a decision that changed the course of South African history.
Sometimes-heated talks between the two and their factions in the end brought about the first all-race elections in 1994 which propelled Mandela to power.
The two men shared the 1993 Nobel Peace Prize for their efforts.