Activists have praised the government's move

The Department of Health has been given until the end of September to develop a plan detailing when and how the drugs will be made available.

Some 4.7 million South Africans, one in nine, are infected with HIV/Aids - the world's highest number.

Aids activists who led an increasingly angry campaign demanding drug treatment, welcomed the government's move but cautioned that they had been disappointed before.

Government shares the impatience of many South Africans on the need to strengthen the nation's armoury in the fight against Aids Cabinet statement

Zackie Achmat, chairman of the Treatment Action Campaign, congratulated the government on a courageous decision, saying it was the best news in four dark years.

"We will wait to see the actual operational plan before celebration," said Mr Achmat, who himself is HIV positive. "But for all of us living with HIV in South Africa, and our families this is the first sign of hope."

The TAC, which often accused the government of playing down the epidemic, said it would formally suspend a civil disobedience campaign and reconsider pending litigation early next week, Reuters reported.

Affordable treatment

It is the first time the South African government has shown commitment towards anti-retroviral drugs, says the BBC's Alastair Leithead in Johannesburg.

Q&A: South Africa and Aids Aids doctor's photo diary

In the past, President Thabo Mbeki has questioned the link between HIV and Aids, and stressed the role of poor quality food and housing in reducing the immunity systems of many South Africans.

Earlier this week the government came under a huge amount of pressure from scientists, community workers and academics at the South African Aids conference in Durban.

The announcement that the drugs would be introduced came after a after a special meeting of the cabinet to discuss the issue of Aids treatment.

It follows a report prepared from a Health Department and Treasury task team which found that the public provision of anti-retroviral drugs was now affordable.

"Government shares the impatience of many South Africans on the need to strengthen the nation's armoury in the fight against Aids," said the cabinet in a statement.

"Cabinet will therefore ensure that the remaining challenges are addressed with urgency and that the final product guarantees a programme that is effective and sustainable."