Johannesburg: South Africa’s last apartheid president FW de Klerk has cut short a visit to Europe because of the ailing health of his co-Nobel peace prize winner Nelson Mandela, his foundation said on Saturday.

“FW de Klerk and his wife Elita have decided to suspend their current working visit and holiday in Europe because of Mr Mandela’s medical condition,” the FW de Klerk Foundation said in a statement.

Mandela was said on Saturday to still be in a critical condition after more than three weeks in a Pretoria hospital suffering a lung infection.

De Klerk — a one-time hard-liner — dismantled apartheid and authorised the release of Mandela from prison in 1990, a decision that changed the course of South African history.

The relationship between the two men has been marked by uneasiness since their sometimes fraught negotiations during the transition from apartheid to democracy.

“At times we had strong clashes, strong words for each other,” De Klerk said at an even in Gabon earlier this month.

And yet, he added: “At all times when there was a crisis... we could always rise above our differences and find accommodation for each other.”

“After his retirement and mine, we’ve become good friends, he has been a guest in my house, I’ve been a guest in his house, we talked regularly on birthdays, and he is a very, very special person, yes, I pray for him and his family.”

For his part Mandela, in a letter dated July 1992, at the height of political violence that shadowed the peace talks, told De Klerk: “You may succeed in delaying, but never in preventing, the transition of South Africa to a democracy.

“Find a way to address the demands we have placed before you with regards to the negotiations deadlock and those relating to the violence so that negotiations can become meaningful.”

But their talks did, in the end, succeed and the two men shared the 1993 Nobel Peace Prize for their efforts, a year before the first multi-racial elections that brought Mandela to power.