Well-wishers hold a giant banner with an image of former president Nelson Mandela as they gather to wish him a happy birthday outside the Mediclinic Heart Hospital, where he is being treated, in Pretoria. REUTERS/Siphiwe Sibeko

Pretoria - Struggle icon Ahmed Kathrada on Thursday encouraged the nation to remember the sacrifices former president Nelson Mandela has made.

“Remember what Madiba stood for and sacrificed all his life. It is to build one united nation under one flag, under one anthem,” he said.

Kathrada was speaking at the Mediclinic Heart Hospital in Pretoria as thousands of South Africans gathered to wish the ailing former statesman well.

Mandela was spending his 95th birthday in the hospital after being admitted on June 8 with a recurring lung infection.

The treason trialist and former Robben Island prisoner reminisced on the ideals Mandela had when he came out of prison, to help shape the country going forward.

He said much still had to be done to achieve those ideals.

“There's a lot that one has to do, because the main message Madiba came out of prison with was his of non-racialism. That means you live in a country of various political beliefs,” said Kathrada.

The principle was evident in how the country turned out.

“He (Mandela) said we have to live in the same country with the same people with the message of forgiveness. With the message of looking forward, reconciliation, and going forward with a stronger united South Africa,” said Kathrada.

Pretoria Central High School headmaster Thomas Hlongwane took his pupils to the hospital to sing happy birthday.

He heaped praise on Mandela and thanked him for being level-headed about the future of the country.

“We have peace and stability in South Africa because he chose the negotiations route instead of the AK47,” said Hlongwane.

He said many people, especially the youth, took for granted some of the things happening in the country.

He told pupils, 20 years ago he could never have dreamt of living in the suburbs of Centurion. He added his hope that Mandela could live up until the age of 100.

“We will have a huge centenary celebration for him,” he said. - Sapa