The United Nations Aids agency has said new HIV infections and deaths from the disease are falling, making it possible to control the epidemic by 2030 and eventually end it "in every region, every country".
A report released by the agency showed that 35 million people around the world were living with HIV. In 2013, there were 2.1 million new cases, 38% less than the 3.4 million figure in 2001.
Aids-related deaths have fallen by a fifth in the past three years, standing at 1.5 million a year. South Africa and Ethiopia in particular have improved.
Many factors have contributed to the improvement, including increased access to drugs. The UN stated there has been a doubling in the number of men opting for circumcision to reduce the risk of spreading or contracting HIV.
However, the report called for a wider international effort as the "current pace cannot end the epidemic" and revealed that while improvements are being made, fewer than four in 10 people with HIV are receiving life-saving antiretroviral therapy.
The human immunodeficiency virus that causes AIDS can be transmitted via blood, breast milk and by semen during sex, but can be kept in check with the cocktail of drugs.
Earlier this week, the World Health Organisation announced that all men who have sex with other men should take antiretroviral drugs, in a bid halt the growing rates of HIV in gay communities around the world, the Independent reported.
The UN report revealed just 15 countries account for three-quarters of all new HIV infections and the charity Médecins Sans Frontières (MSF) warned most of those in need of HIV drugs still had no access to them.
In Nigeria, 80% of people do not have access to treatment.
"There have been more achievements in the past five years than in the preceding 23 years," the report said. "There is evidence about what works and where the obstacles remain, more than ever before, there is hope that ending Aids is possible.
"However, a business-as-usual approach or simply sustaining the Aids response at its current pace cannot end the epidemic."
Michel Sidibe, the executive director of UNAIDS, told BBC News: "If we accelerate all HIV scale-up by 2020, we will be on track to end the epidemic by 2030, if not, we risk significantly increasing the time it would take - adding a decade, if not more."
In 2011, UN member states agreed to a target of getting HIV treatment to 15 million people by 2015. As countries scaled up treatment coverage, the World Health Organisation set new guidelines last year, expanding the number of people needing treatment by more than 10 million.
Jennifer Cohn, medical director of the access campaign at MSF, said: "Providing life-saving HIV treatment to nearly 12 million people in the developing world is a significant achievement, but more than half of people in need still do not have access."