The top advisor on AIDS to US President George W Bush has warned that the world is losing the battle against the disease.
Dr Anthony Fauci told an international AIDS conference in Australia that more people were being affected with HIV than were receiving treatment.
The conference in Sydney also heard that the lack of health services is in nations worst hit by the disease is now the biggest challenge in the AIDS battle.
The head of the World Bank's HIV/AIDS programme said that while some two million people were now receiving treatment, the lack of health services in many African and Asian nations was adversely affecting treatment programmes.
An absence of proper pharmaceutical storage had seen drugs expire before they could be administered and a so-called brain drain of doctors and medical researchers meant there was a shortage of people capable of properly implementing treatment, she said.
The International Aids Society conference is the world's largest summit on the disease, attended by 5,000 delegates from 133 countries.
The United Nations says close to 40 million people are infected with the AIDS virus and that treatment had dramatically expanded from 240,000 people in 2001 to 1.3 million by 2005.
In June, world leaders at the G8 summit in Germany set a target of providing AIDS drugs over the next few years to approximately 5 million people.
A report by Médecins Sans Frontières at the conference said that while there had been dramatic price reductions in some HIV/AIDS drugs, the newer, less toxic drugs recommended by the World Health Organisation had become more expensive.
