WASHINGTON - President Obama acknowledged an uncomfortable reality as he announced the nation's first comprehensive national HIV/AIDS strategy at a White House ceremony Tuesday: While the United States has made tremendous gains treating people infected with the virus, efforts to prevent the spread of the disease have continued to lag.

Even as the federal government spent tens of billions of dollars to develop and administer new drugs for HIV patients, the number of new people infected every year has remained virtually unchanged for a decade.

An estimated 1.1 million Americans are living with HIV, the virus that causes AIDS, with 56,000 new infections annually.

"We are keeping pace when we should be gaining ground," Secretary of Health and Human Services Kathleen Sebelius said Tuesday at the White House.

The strategy sets a goal of reducing new infections by 25 percent over the next five years; getting treatment for 85 percent of patients within three months of their diagnosis; and increasing education about the virus, even in communities with low rates of infection.

"Fighting HIV/AIDS in America and around the world will require more than just fighting the virus," Obama said at a White House reception honoring the work of those in the HIV and AIDS community. "It will require a broader effort to make life more just and equitable."

The plan includes more than 100 specific directives to federal agencies to develop standards for assessing prevention programs, build new education campaigns for ethnic communities, step up screening of federal prisoners, and take scores of other steps over the next year and a half to meet the new goals.

Georges C. Benjamin, executive director of the American Public Health Association, called the new national strategy "a lifesaving public-health intervention," echoing widespread praise for the new strategy.

For many who have been laboring to control HIV/AIDS, the specific steps are particularly welcome after years of disappointing progress.

"It outlines these really important points in curbing this epidemic," said Nurit Shein, executive director of the Mazzoni Center, a treatment organization in Philadelphia: "reducing rates of infection, [increasing] access to care, minimizing the stigma, and tailoring prevention" to high-risk groups.

American public-health efforts in the 1980s and early '90s helped dramatically cut new infections by more than half. But there are now slightly more new infections a year than there were in the early '90s, when they bottomed out at about 49,000 a year, the Centers for Disease Control and Prevention estimates. And an estimated one person in five infected with HIV today does not know it - a rate the new strategy aims to cut in half by 2015.

Particularly disturbing to many activists has been the persistently high infection rates among gay and bisexual men, who account for more than half of all new infections, and among African Americans.

Black men and women account for 46 percent of people living with HIV, though they represent just 13 percent of the population, according to the CDC. Infection rates for black men are particularly high in Philadelphia, where heterosexual black women also are infected at higher rates than nationally.

"I am ecstatic that our nation finally has a real comprehensive HIV strategy," said Gary J. Bell, executive director of Bebashi, an AIDS services organization in the city's African American community. "Unfortunately at times the issue of HIV has been hijacked by special interests who thought it was a gay disease, to those who thought abstinence was the only strategy, to those who thought that money shouldn't be going toward the issue at all."

The strategy aims to copy some of the steps credited with spurring the success of a Bush administration policy to fight AIDS in hard-hit developing countries. That includes setting specific targets and mandating coordination among different government agencies to guard against missteps and wasted, duplicated efforts.

"We've never had that kind of coordinated, accountable effort to address AIDS in America, and that's what we need," said Chris Collins of the Foundation for AIDS Research, one of the many groups who advised administration officials during the months-long process of devising the strategy.

But many experts say the prevention efforts have not kept pace with the development of powerful new drugs that allow many people with HIV to live relatively normal lives. Part of the challenge, they said, is the very success produced by medical breakthroughs, which has led to less vigilance about, for example, avoiding unprotected sex.

Many also feel that prevention is underfunded. An estimated 4 percent of the federal government's $19 billion domestic HIV/AIDS budget goes to prevention. And while the administration is allocating $30 million from the massive health-care overhaul Congress passed earlier this year toward implementation of the new plan, cities and states around the country have been cutting prevention funding in attempts to balance their budgets.

While most AIDS advocates applauded Obama's new plan, they were also realistic.

"I think it's a beginning. I don't think it's enough, but I think it is setting us in the right direction to curb this epidemic," said Shein of the Mazzoni Center, which provides health services to Philadelphia's gay, lesbian, bisexual, and transgender community.

Staff writer Brooke Minters contributed to this article, which also contains material from the Associated Press.