President Obama told activists, patients, scientists and business leaders gathered in Washington on Thursday to mark World AIDS Day that his administration will do more to get life-extending antiretroviral drugs for those infected with HIV — both in the United States and in low-income countries.

The administration will provide an additional $35 million to states to help them buy AIDS drugs for people who can’t afford them and $15 million to clinics that care for those patients, the president said in a speech at George Washington University.

About 6,600 low-income HIV-positive people are on drug waiting lists in 12 states. The new money would pay for medication for about 3,000 people. The cost of medicine for people using state-sponsored AIDS drug assistance programs (ADAPs) was $11,388 per person last year.

The audience of about 300 people gave Obama a standing ovation when he said the government’s overseas AIDS program will seek to get 6 million people on antiretroviral therapy by the end of 2013. At the moment, treatment for about 3.9 million is underwritten by the President’s Emergency Program for AIDS Relief (PEPFAR).

The more ambitious schedule won’t need additional funding, but will require greater efficiencies in the global AIDS program, which President George W. Bush started in 2003. Its budget this year is $6.6 billion, and in recent years it has worked hard to, among other things, streamline drug procurement and delivery in 80 countries with PEPFAR-funded programs.

“This is a global fight and it is one that America must continue to lead,” Obama said. “We’ve come so far and we’ve saved so many lives, we might as well finish the fight.”

About $1 billion of this country’s overseas AIDS spending is in the form of a donation to the Global Fund to Fight AIDS, Tuberculosis and Malaria. Based in Geneva, the fund provides grants to hundreds of treatment and prevention programs in the developing world and underwrites antiretroviral therapy for 3.3 million people.

It receives nearly all its money from rich countries, but a number of European nations, including Italy and Spain, have not fulfilled recent pledges. Obama did not name them, but said that countries “need to give the money they promised.” He did, however, name China as a country that was once a recipient of Global Fund grants but should now “transition” to becoming a donor.

Bush spoke by video link from Tanzania, along with that country’s president, Jakaya Mrisho Kikwete. Bush, his wife and two daughters are in Africa to promote his charitable foundation’s efforts to improve screening for and treatment of breast and cervical cancer.

“It’s not acceptable to save a woman from AIDS and watch her die from cancer,” he told the gathering.

Former president Bill Clinton also spoke, by video link from Florida, making a suggestion that took much of the audience by surprise.

He proposed that Congress allow generic versions of patented AIDS drugs to be sold in the United States under certain circumstances for the next two years. Currently, these generic copies, mostly made in India, are only to be used in low-income countries because they are still protected by patents in the United States and other rich countries.

In two years, “the economic picture will be better and the health-care reimbursement system will be different,” Clinton said, referring to the start of near-universal health insurance through the Obama administration’s Affordable Care Act.

The people who would be eligible for low-price generic medication would presumably be those now receiving them through state AIDS drug assistance programs, or on ADAP waiting lists. Details of his proposal were not available.

“That is a proposal that deserves serious consideration,” said Anthony S. Fauci, head of the National Institute of Allergy and Infectious Diseases, the branch of the National Institutes of Health chiefly responsible for U.S. AIDS research.

ADAPs help buy AIDS medicine for about 200,000 Americans with HIV. The programs, which exist in every state, had total budgets of $1.8 billion last year, with about $850 million provided by the federal government.

The GW event was sponsored by ONE and (Red), two advocacy organizations fighting disease and poverty, principally in Africa. It featured a roundtable discussion, led by CNN correspondent and physician Sanjay Gupta, that included U2 singer Bono, singer Alicia Keys, the chairman of Coca-Cola, two members of Congress, an American religious leader, a South African woman who lost a daughter to AIDS and is herself infected and a Ghanaian physician.

The speakers repeatedly thanked the United States for spending money to save people who aren’t Americans from death by AIDS.

“I’m not an American, so you have to listen to me,” said Bono, who is Irish. “Thank you, thank you, thank you to the United States.”

Florence Ngobeni, the South African woman who said she is now healthy and working as a health educator, said: “I tell you, PEPFAR is the only program that I have had for my entire life living with HIV.”