President Bush's endorsement Tuesday of a bill to sharply increase U.S. funding for the fight against AIDS in Africa and the Caribbean sets the stage for expected congressional approval of the legislation in coming weeks. However, some conservatives remain unhappy with the legislation.

At a White House ceremony, President Bush praised legislation that would result in $15 billion in U.S. spending on AIDS over the next five years, and urged both houses of Congress to approve it.

"HIV/AIDS is a tragedy for millions of men, women and children, and a threat to stability of entire countries and of regions of our world. Our nations have the ability, and therefore the duty, to confront this grave public health crisis," he said.

The legislation focuses on 14 countries in Africa and the Caribbean. It would provide $1 billion almost immediately to the U.N. Global Fund on AIDS, and would create a new post of coordinator to manage U.S. government activities to fight AIDS.

The bill cites as a role model Uganda's approach to AIDS prevention, called "ABC" or Abstain, Be Faithful, Use Condoms. It is credited for reducing AIDS infection rates there from 30 percent to six percent since 1987.

However, some conservative lawmakers oppose the bill in its current form, saying it places too much emphasis on condom use, and not enough on abstinence and monogamy.

President Bush's endorsement of the legislation has been criticized by some "social conservatives" and by groups who believe some of the money may go to projects supporting abortion.

In a briefing before the White House ceremony, White House spokesman Ari Fleischer was asked several times about these criticisms. "The president would like to call attention, wherever there are critics, whether they are on the left or on the right, to a success that works. And the Ugandan model is a great role model," he said. "It provides a focus on abstinence, it puts an emphasis on abstinence, and yet it recognizes that that alone is not the only answer, but it is an effective model of fighting AIDS in Africa."

Mr. Fleischer noted that under the president's original AIDS initiative, announced last January, any organization would be eligible to participate, provided it doesn't use the funds to perform or promote abortion.

Earlier this month, the Republican-led House International Relations Committee rejected an effort by conservatives to strengthen language in the bill in favor of abstinence.

The president's endorsement is not likely to dissuade these lawmakers from offering amendments when the legislation comes up for debate in the full House and Senate.

Late Tuesday, the ranking Democrat on the House International Relations Committee, Tom Lantos, vowed to work with the committee's Republican chairman, Henry Hyde, to oppose any attempts to weaken the legislation.

"I fully anticipate that there may be amendments to try to undermine our approach. And I will lead the fight to defeat those amendments," he said.

President Bush wants lawmakers to approve the AIDS bill before the next congressional recess at the end of May.

The legislation could come up for a vote in the House as early as this Thursday. A Senate version could be finalized by the Foreign Relations Committee next week.