Washington DC - The world needs roughly an additional $7 billion every year to fight HIV/AIDS, and the lack of that money is killing people.

That's what Michel Sidibe, executive director of UNAIDS, the joint United Nations Program on HIV/AIDS, said at the opening of the XIX International AIDS Conference, also known as AIDS 2012.

At least 22,000 scientists, policymakers, people living with HIV and others plan to attend AIDS 2012, which started this week in Washington DC.

The biennial event is the world's largest meeting on AIDS. Every year, leading scientists go to it to deliver reports on recent AIDS research and to work with community leaders and policymakers to identify the next steps and goals in the global fight against AIDS.

"The financial commitment from developed countries has been declining," he said. "When investment in HIV/AIDS is cut, the epidemic will continue to ruin lives and damage communities."

Donors and national policymakers need to provide money for HIV/AIDS projects, especially since it has been proved that the spread of the disease can be slowed by giving support to preventative measures, said Elly Katabira, AIDS 2012 International Chair and President of the International AIDS Society.

To ensure the support going to AIDS/HIV projects is adequate, Michel Sidibe said, many people are starting to call for the adoption of a financial transaction tax, which could help raise money for that purpose.

He also praised various developing countries for spending more on AIDS control.

Throughout the world, more than 80 low- and middle-income countries increased the amount of money they were spending to fight AIDS by at least 50 percent between 2006 and 2011, he said.

So far, more than 34 million people are infected with HIV globally, UNAIDS statistics show.