Secretary of State Hillary Clinton announced $150 million in new funding for global efforts against AIDS, insisting that the United States remains devoted to fighting the disease.
"The United States is committed and will remain committed to achieving an AIDS-free generation," she said.
Clinton made the announcement Monday at the International AIDS Conference, the world's largest gathering on the disease.
The new U.S. donation will support treatments for pregnant women with HIV, voluntary circumcisions for men, and several research and civil-society projects, Clinton said.
She acknowledged critics, many at the event, who believe the United States has lost focus on the AIDS fight.
"I’ve heard a few voices from people raising questions about America’s commitment," she said, adding, "We will not back off. We will not back down."
Clinton called ending mother-to-child transmission and encouraging male circumcision, which lowers the risk of men contracting HIV during sex with women, "priorities."
On a personal note, she said that her first view of the celebrated AIDS quilt on the National Mall in 1996 was "devastating."
"We are all here today because we want to bring about that moment when we stop adding names," she said, "when we can come to a gathering like this one and not talk about the fight against AIDS, but instead commemorate the birth of a generation that is free of AIDS."
The International AIDS Conference has not been held in the United States for two decades because of laws that previously barred people with HIV from entering the country.
Major leaders are scheduled to speak, including former President Clinton, World Bank President Jim Yong Kim and philanthropist Bill Gates.
Obama is one of the few heads of state not to attend the conference in his own country. He delivered a video message to welcome attendees, according to the White House.
Health and Human Services Secretary Kathleen Sebelius also addressed the gathering on Sunday.
–This post was updated at 8:26 a.m. Tuesday. A previous version incorrectly stated that Clinton had pledged $80 million, not $150 million.