WASHINGTON--President Bush will call on Congress Wednesday to provide $30 billion toward battling the global AIDS crisis over the first five years after he leaves office, according to senior administration officials, a doubling of the current U.S. commitment.

The increase in the President's Emergency Program for AIDS Relief (PEPFAR) would provide lifesaving treatment to 2.5 million people, administration officials said Tuesday night -- some 1.4 million more than are currently served by the program.

The program's original five-year mandate, which provided for $15 billion in U.S. funding, expires in September 2008. Bush's plan would extend that for five more years.

Bush will issue his request Wednesday afternoon, the officials said, during a Rose Garden ceremony where he is scheduled to be joined by supporters and beneficiaries of the program, including a caregiver and an AIDS patient. At the same time, the president will announce that first lady Laura Bush will travel to Africa in late June and visit AIDS-related services funded by the program in Zambia, Mali, Mozambique and Senegal, officials said.

Bush's announcement comes in a week when he is highlighting his administration's commitment to international development and human rights protections, both of which will be major items for discussion next week when he joins other world leaders at a Group of Eight summit meeting in Germany. Tuesday, Bush announced new economic sanctions on Sudan, and he is also expected Wednesday to nominate veteran diplomat Robert Zoellick as president of the World Bank.

AIDS advocates hailed word of the president's plans.

"We think a doubling is definitely in order," said Paul Zeitz, executive director of the Washington-based Global AIDS Alliance. "I would call it bold action. Is it enough? No. Do we have to have better policies? Yes. But PEPFAR is still a breakthrough and has had a significant impact."

Globally, some 40 million people suffer from HIV/AIDS, a number that has been fast increasing despite growing prevention efforts.

Bush announced the program, the largest foreign-aid effort directed at a single disease in U.S. history, in his 2003 State of the Union address. Through last September, it was paying for anti-retroviral treatment for 822,000 people in the "target countries" -- 12 African nations, Guyana, Haiti and Vietnam.

The program also pays for drugs for 165,000 people elsewhere in the developing world, and it has provided short courses of medicine to more than 500,000 pregnant women, a strategy that has prevented about 100,000 infections to newborns, program officials say.

Earlier this year, an independent panel of experts assembled by the Institute of Medicine called the massive program "well positioned" to help AIDS-devastated countries control their epidemics.

Many advocacy groups, while praising the ambitious reach, have criticized the program for its congressionally-imposed emphasis on abstinence education. Nearly 7 percent of the money is tied to abstinence education. Also, some have been critical that only a fraction of the money is funneled into multinational efforts to battle AIDS.

"PEPFAR has done a lot of good," Zeitz said. "But it could have done more."

Rep. Tom Lantos, D-Calif., chairman of the House Committee on Foreign Affairs, called the president's planned announcement "music to my ears." But, he added, much more must be done.

Bush's announcement comes at an unusual time, as the legal authority for the program does not expire until September 2008 and Congress has already held one hearing in preparation for its reauthorization.

But administration officials said he wanted to make the announcement in advance of next week's summit, during which Bush is likely to take criticism for his administration's positions on climate change.