- NEW: In Sub-Saharan Africa, about 22.9 million people are living with HIV, the U.N. says
- NEW: Nearly half of the 4.8 million Asians living with HIV reside in India, the U.N. adds
- Roughly 50,000 people in the U.S. become infected with the disease each year
- About 1.2 million Americans are currently living with HIV, the White House says
"We are going to win this fight," Obama said. "But the fight's not over, not by a long shot."
He said the United States will also begin an ambitious plan to help countries around the world, raising its target of helping 6 million people access treatment by the end of 2013.
Obama added that the U.S. plans to host the World AIDS conference next year, having removed a ban that prohibited people with HIV from entering the country.
"We can beat this disease," Obama added.
Via satellite, former Presidents George W. Bush and Bill Clinton also attended the event, which marked 30 years since the deadly virus was first discovered.
"I understand we're in tight budget times," Bush said. But he emphasized that "I believe we are required to support effective programs that save lives."
Bush urged a renewed commitment among nations in the effort to stem the spread of the virus.
Clinton also weighed in Thursday, saying there still is a pressing need to reduce the cost of anti-retroviral drugs and expand treatment to rural areas, particularly in some of the virus's hardest hit regions.
In Sub-Saharan Africa, about 22.9 million people are living with HIV, the virus that causes AIDS, according to a recent U.N. report. Nearly half of the 4.8 million Asians living with HIV reside in India, the report added.
In the United States, about 1.2 million Americans are currently living with HIV, and roughly 50,000 people become infected with the disease each year, according to a White House statement.
More than 600,000 Americans have died from the virus since it was discovered.
Thursday's event was moderated by CNN Chief Medical Correspondent Sanjay Gupta, with panel discussions by musicians Bono and Alicia Keys, as well as Mexican businessman Carlos Slim
Gupta noted the virus is now "on the run." But, he added, "it is the worst time to sit back and say 'job well done.'"
A November U.N. report found that increased access to HIV services has contributed to a 15% drop in new infections over the past ten years, as well as a 22% reduction in AIDS-related deaths over the last five years.
"2011 has been a game changing year," said Paul De Lay, deputy director of UNAIDS. "With new science, unprecedented political leadership and continued progress in the AIDS response, countries have a window of opportunity to seize this momentum and take their responses to the next level."