the region’s richest nation

the region’s richest nation South Africa, the region’s richest nation and a symbol of democracy, has an estimated 5.7 million H.I.V.-positive citizens, more than any other country.

“In my village, when we want to kill the snake, we don’t hit the tail, but the head,” said Mr. Sidibé, who is from Mali. “The head of this epidemic is South Africa.”

The South African Finance Ministry said it expected that the broadened access to drugs would put a million more people on treatment in the next few years, roughly doubling the current case load. It has budgeted an extra $1 billion for it. Dr. Motsoaledi said that Mr. Zuma reopened the budget to get more money for AIDS when it became clear that costs would be higher.

South Africa’s understaffed public health system and the ballooning cost of treating millions of people for life will pose daunting challenges to the government’s ambitious goals.

The United States has long been South Africa’s principal donor in the fight against AIDS, giving the country $620 million this year. But advocates worry that global donors will not provide enough money to sustain a rapidly growing treatment program.

Mr. Mbeki had questioned whether H.I.V. caused AIDS and suggested that anti-retroviral drugs were harmful. Harvard researchers estimated that the government could have prevented the premature deaths of 365,000 people during the last decade if it had provided the drugs to AIDS patients and medicines that help stop pregnant women from infecting their babies.

“If we had acted more than a decade ago, we might not have been in this situation where we are,” Dr. Motsoaledi said. “Obviously, we did lose time.”

Mr. Zuma, in office for almost a year, has broken sharply with the Mbeki record, broadening access to AIDS drugs for H.I.V.-positive pregnant women and babies, as well as for people with tuberculosis. The government is moving toward routinely offering H.I.V. tests to all who come into Positive Platethe public health system, rather than waiting for people to ask for them.