On the final day of the largest-ever conference on Aids, Nelson Mandela has said he "cannot rest" until the tide against the HIV pandemic is turned.
Mandela and Annan say rich countries should do more
He urged rich countries to inject more cash into the Global Fund, a body created in 2002 to fight epidemics.
UN General Secretary Kofi Annan earlier criticised the United States for failing to fight Aids with the same resolve it shows in the war on terror.
Some two-thirds of the world's 38m HIV positive people live in Africa.
"History will surely judge us harshly if we do not respond with all the energy and resources that we can bring to bear in the fight against Aids," Mr Mandela, who turns 86 on Sunday, said at the 15th International Aids Conference in Thailand's capital, Bangkok.
"I cannot rest until I am certain that the global response is sufficient to turn the tide of the epidemic," he added.
US under fire
The six-day conference, attended by nearly 20,000 scientists, focussed mainly on how to get more anti-retroviral drugs to patients in the developing world.
In this context, the US came under attack for its drug-funding policy, mainly based on bilateral deals, and for pushing abstinence as a form of prevention rather than encouraging the use of condoms.
US officials claimed that their county's contribution to fight Aids was more than that of the rest of the world put together, and ruled out increasing their donations to the fund.
But the head of the European Union delegation on Friday replied that 60% of contributions to the fight against the pandemic come from its coffers.
Delegates at the conference also stressed the percentage of women among the infected was on the rise, and warned that Asia, and particularly India, was a time-bomb that required immediate action.
Of the 38 million HIV-positive people in the world, nearly half are women and 25 million live in sub-Saharan Africa.