President Bush marked World AIDS Day as a time to remember the United States' responsibility to help the 39 million people living with the disease around the world.

"The pandemic of HIV/AIDS can be defeated," Bush said Friday in the Roosevelt Room, where he and the first lady met with Health and Human Services Secretary Michael Leavitt, U.S. Global AIDS Coordinator Mark Dybul and community leaders from the U.S. and Africa.

"It's a day, as well, for the United States to remember that we have a duty to do something about this epidemic — this pandemic," Bush said about the disease, which has killed 25 million people.

Bush called on Congress to reauthorize the $2.1 billion Ryan White Care Act, the largest federal program specifically for people with HIV/AIDS. Supporters say changes are needed in the act because AIDS has moved beyond urban centers into rural areas. But in September, they failed to overcome objections from senators in New York and New Jersey, states that stand to lose more than $70 million each under revisions to the act.

Bush's AIDS initiative, announced in 2003, is the largest international health initiative dedicated to a single disease.

It targets 15 countries that are home to about half of the world's 39 million people who are HIV-positive. The countries are: Botswana, Cote d'Ivoire, Ethiopia, Guyana, Haiti, Kenya, Mozambique, Namibia, Nigeria, Rwanda, South Africa, Tanzania, Uganda, Vietnam and Zambia.

The Bush initiative committed $15 billion over five years to support treatment for 2 million people, prevention for 7 million and care for 10 million. The White House says that before the program , there were about 50,000 people receiving lifesaving drugs, and that today, there are more than 800,000 people receiving the drugs.

But while the treatment program is widely praised, critics of Bush's initiative complain that not enough is being done to prevent people from contracting HIV.

Richard Holbrooke, former U.S. ambassador to the United Nations who now leads the Global Business Coalition on HIV/AIDS, said the treatment program might not be sustainable, because the number of people with HIV continues to grow. According to the U.N. agency on AIDS, there will be 4.3 million new infections this year.

Proponents of the Bush initiative argue a three-pronged HIV prevention strategy — emphasizing abstinence, fidelity and condom use — offers people the best options to protect themselves from AIDS. Democrats in Congress have condemned a provision in the Bush initiative that requires that 33 percent of all money committed to prevention programs be spent to promote abstinence. That restriction, they say, has more to do with conservative ideology than scientifically proven successful programs.