JOHANNESBURG - Former South African President Nelson Mandela's condition deteriorated to "critical" on Sunday, the government said, two weeks after the 94-year-old anti-apartheid leader was admitted to hospital with a lung infection.
The worsening of his condition is bound to concern South Africa's 53 million people, for whom Mandela remains the architect of a peaceful transition to democracy in 1994 after three centuries of white domination.
A government statement said President Jacob Zuma and the deputy leader of the ruling African National Congress (ANC), Cyril Ramaphosa, visited Mandela in his Pretoria hospital, where doctors said his condition had gone downhill in the last 24 hours.
"The doctors are doing everything possible to get his condition to improve and are ensuring that Madiba is well looked after and is comfortable," it said, referring to him by his clan name.
Mandela, who became South Africa's first black president after historic all-race elections nearly two decades ago, was rushed to a Pretoria hospital on June 8 with a recurrence of a lung infection, his fourth hospitalization in six months.
Until Sunday, official communiques had described his condition as "serious but stable" although comments last week from Mandela family members and his presidential successor, Thabo Mbeki, suggested he was on the mend.
Since stepping down after one term as president, Mandela has played little role in the public or political life of the continent's biggest and most important economy.
His last public appearance was waving to fans from the back of a golf cart before the final of the soccer World Cup in Johannesburg's Soccer City stadium in July 2010.
During his retirement, he has divided his time between his home in the wealthy Johannesburg suburb of Houghton, and Qunu, the village in the impoverished Eastern Cape province where he was born.
The public's last glimpse of him was a brief clip aired by state television in April during a visit to his home by Zuma and other senior ANC officials.
At the time, the 101-year-old liberation movement, which led the fight against white-minority rule, assured the public Mandela was "in good shape" although the footage showed a thin and frail old man sitting expressionless in an armchair.
"Obviously we are very worried," ANC spokesman Jackson Mthembu told Johannesburg station Talk Radio 702. "We are praying for him, his family and the doctors.""It's time to let Mandela go"
Since his latest admission to hospital, well-wishers have been arriving at his Johannesburg home, with scores of school-children leaving painted stones outside the gates bearing prayers for his recovery.
However, for the first time, South African media have broken a taboo against contemplating the inevitable passing of the father of the post-apartheid "Rainbow Nation" and one of the 20th century's most influential figures.
The day after he went into hospital, South Africa's Sunday Times
newspaper carried a front-page headline saying it was "time to let him go."
In Washington, US President Barack Obama's National Security Council spokeswoman Caitlin Hayden said the White House has seen the reports on Mandela's health. "Our thoughts and prayers are with him, his family and the people of South Africa," she said.
Obama is scheduled to visit South Africa with his family later this week. On Friday, a White House adviser said the president would defer to the Mandela family's wishes on any contact with the former South African leader.
Despite the widespread adulation for Mandela, he is not without detractors at home and in the rest of Africa who feel that in the dying days of apartheid he made too many concessions to whites, who make up just 10 percent of the population.
After more than 10 years of affirmative action policies aimed at redressing the balance, South Africa remains one of the world's most unequal societies, with whites still controlling much of the economy and the average white household earning six times more than a black one.
"Mandela has gone a bit too far in doing good to the non-black communities, really in some cases at the expense of (blacks)," Zimbabwean President Robert Mugabe, 89, said in a documentary aired on South African television this month.
"That's being too saintly, too good, too much of a saint."