The United Nations' top HIV/Aids official says it is no longer realistic to hope that the world will meet its goal of halting and reversing the spread of the pandemic by 2015.
Peter Piot, head of the UN campaign to combat Aids, told reporters at an Aids conference that it was still "possible" to reach that goal and some countries would get control of the disease.
But HIV/Aids was spreading much faster than efforts to rein it in crucial regions, including Eastern Europe and Central America, and stopping the spread was unrealistic, he said.
"What we are faced with is multiple epidemics, and that the epidemic is still expanding," Mr Piot said.
"We are actually still moving into the globalisation of the Aids epidemic." The remarks were a rare case of a UN official admitting that at least one of the Millennium Development Goals - a host of aspirations world leaders laid out in 2000 to be achieved by 2015 - will probably not be met.
World leaders frequently say that other goals on development, tackling poverty, and ensuring universal elementary education will be tough to meet.
The conference Mr Piot is attending is being held to review progress towards meeting targets set at a UN General Assembly Special Session on HIV/Aids in 2001 to start tackling the crisis.
A few hours before Mr Piot spoke, UN secretary-general Kofi Annan warned the conference that the Aids epidemic was accelerating on every continent. He noted that just 12 per cent of the people who needed anti-retroviral therapies in poorer countries were getting them.
Saying the fight against HIV/Aids may be "the great challenge of our age," Mr Annan called for more money and more vocal leadership. Efforts so far had not "matched the epidemic in scale", he said.