Mr. Bush was said to be closer to a decision on the military.
At the same time, officials said the president was comfortable with proposals to eventually offer the smallpox vaccine to all Americans, beginning with health care workers most likely to come into contact with a contagious patient. He has not, however, signed off on key details or a final plan.
Mr. Bush's top bioterrorism aides agree the vaccine should eventually be offered to the general public. At issue is how fast to move ahead.
A once-feared disease, smallpox historically killed 30 percent of its victims. The highly contagious virus, for which there is no known treatment, also could be a powerful weapon. Routine vaccinations in the United States ended in 1972, making the population highly vulnerable to an attack.
But the vaccine, made from a live virus, is also dangerous. Health experts estimate that one or two of every million people vaccinated for the first time will die, and about 15 others will suffer life-threatening side effects.
Under the proposal for the military, the first personnel to receive the vaccine would be "first responders" — troops responsible for assisting in domestic disasters, such as a bioweapons attack. They include medical specialists.
As many as 500,000 troops might eventually be inoculated, senior defense officials have said. Of the 1.4 million men and women in the active-duty military, fewer than half have ever received the smallpox vaccine.
Mr. Bush is moving toward smallpox decisions as possible war looms with Iraq, which U.S. intelligence officials believe has smallpox samples.
Amid heightened concerns, the Pentagon is pushing to provide every available form of protection for troops who might be exposed to germ weapons in Iraq or elsewhere. Unlike the civilian vaccination program, which would be entirely voluntary, troops would be required to get the shots.
Vice President Dick Cheney, a former defense secretary, is among those who have pushed most aggressively for protecting the military and the general civilian population against smallpox attack.
The Department of Health and Human Services has set aside about 1 million doses of smallpox vaccine for the military. Those doses are expected to be provided from the 1.7 million doses that have been licensed by the Food and Drug Administration.
Mr. Bush has postponed announcing a decision on vaccinating the civilian population until after he returns from a NATO summit in Europe on Nov. 23. Aides said they did not know when he would disclose his decision on vaccinating troops.
For the civilian population, top health officials favor offering the shots first to people on special smallpox response teams and to those who work in hospital emergency rooms. Next would be about 10 millions others, including emergency responders and other health care workers. Eventually, the vaccine would be offered to the general public, though not until there was enough FDA-approved vaccine available, probably in early 2004.
Some in the White House favor moving ahead more quickly, offering it to the general public even before FDA approval.