Mandela, 85, is starting to take things easy

Mr Mandela, 85, said he wanted to spend more time with his family and friends, complete his memoirs, read and engage in "quiet reflection".

He has been South Africa's highest-profile ambassador, recently lobbying to host the 2010 football World Cup.

He spent 27 years in prison but came out to become South Africa's first black leader in 1994.

Since stepping down as president in 1999, Mr Mandela has been actively involved in the fight against HIV/Aids, which affects some five million South Africans.

'Don't call me'

The BBC's Hilary Andersson in Johannesburg says that Mr Mandela announced his plans to dramatically scale back his public appearances with his usual charm and humour.

"Don't call me, I'll call you," he warned anyone thinking of inviting him to future public engagements.

MANDELA TIMELINE 1918 - Born in the Eastern Cape 1956 - Charged with high treason, but charges dropped 1964 - Charged again, sentenced for life 1990 - Freed from prison 1993 - Wins Nobel Peace Prize 1994 - Elected first black president 1999 - Steps down as leader Profile: Nelson Mandela

"I'm turning 86 in a few weeks time and that is a longer life than most people are granted.

"I am confident that nobody here present today will accuse me of selfishness if I asked to spend time while I'm still in good health with my family, my friends and also with myself," said the former Nobel peace prize winner.

Our correspondent says that he has started to show real signs of frailty, although those close to him say he is in excellent health.

He now walks slowly, sometimes with a cane, his legs suffering from the arduous 27 years he spent in jail.

One of the world's most respected leaders, Mr Mandela, known in South Africa by his clan name Madiba, was diagnosed with prostate cancer in 2001.

As well as flying to Switzerland to lead South Africa's bid to host the football World Cup, he has also attended Spain's royal wedding and met US boxing promoter Don King in recent weeks.

Last month, South Africa's parliament made an exception to its normal rules to let Mr Mandela make a farewell speech.