WASHINGTON -- President George W. Bush requested $7.1 billion to fund his three-part preparation strategy for a flu pandemic, whether it's caused by the bird flu or some other strain.

He asked Congress for the cash on an emergency basis, saying if lawmakers wait for a pandemic to appear, "It will be too late."

Scientists all over the world are sounding the alarm that a virus infecting birds could mutate and gain the ability to move easily among people.

Speaking Tuesday at the National Institutes of Health, Bush said nobody knows when or where a deadly strain of flu will strike. But he said, "At some point, we are likely to face another pandemic."

Bush said $2.8 billion would go toward boosting the technology of developing vaccines.

He also said Congress needs to approve liability protection for the makers of vaccines to encourage more manufacturers to undertake the production.

Bush said scientists can't produce an accurate vaccine for a pandemic until they get a sample of a pandemic strain. However, a vaccine is under development to protect against the current H5N1 strain. He asked Congress to approve $1.2 billion to allow the Department of Health and Human Services to buy enough of the current vaccine to inoculate 20 million people.

Bush also said the government would stockpile the antiviral medications Tamiflu and Relenza.

The president's other two strategies include a worldwide initiative to detect avian flu anywhere in the world and quickly relay the information to governments and international agencies.

"A pandemic is a lot like a forest fire," he said; if it's caught early, it can be contained.

Bush also aims to boost funding for federal and local pandemic preparedness. He said such an effort "will require the active participation of the American people."

Earlier, Health and Human Services Secretary Michael Leavitt said all Americans should have access to vaccines if a pandemic hits the nation.

Leavitt told CBS there's no reason to believe the mutation will occur. But he also said the country must be prepared.

A White House spokesman said all Americans can do their part in stopping the spread of the flu by staying home if they get sick. He said a pandemic could force restrictions of international travel and commerce.

• More Information: PandemicFlu.gov

Bush Wants To Help Vietnam Fight Bird Flu

Bush's battle plan against a possible flu pandemic includes help for Vietnam.

Vietnam has suffered the most human deaths from the bird flu.

The president proposes spending $18 million to manufacture and test a human vaccine in Vietnam.

Leavitt has met with scientists in Vietnam who are working on a vaccine. He said he offered U.S. help in setting up trials to test their effectiveness.

More than 40 people have died in Vietnam from bird flu. Most deaths were from contact with sick animals.

Asia Plans Flu Drill

Countries dealing with bird flu in the Asia-Pacific region are preparing for a pandemic dry run.

Next year, they plan to stage a mock disease outbreak to gauge how well they would respond to a pandemic or other major health threat.

An Australian official said the exercise will try to identify major weaknesses in preparedness and coordination. The focus will be strategy, not field exercises.

The plan was announced Tuesday at the end of a two-day meeting in Brisbane of disaster coordination experts.

The deadly H5N1 strain of bird flu began jumping from birds to people in late 2003. Since then, it has killed at least 62 people in Southeast Asia.

Health experts have warned if the current virus mutates into a form that is easily spread from human to human, it could set off a pandemic and kill millions of people.