Three days before animal-rights groups gather here from around the country for their first national rally, the Bush administration's top health official called the protesters "terrorists" who have disrupted valuable medical research and wasted millions of tax dollars.

Health and Human Services Secretary Louis W. Sullivan said he was "saddened" and "angry" about the nation's growing animal-rights movement. He accused those advocating an end to use of animals in research of putting scientists "on the defensive, through intimidation and even violence" and of being "on the wrong side of morality."

"It would be evil to forsake vital animal research when lives hang in the balance," he said.

Animal-rights activists responded angrily to Sullivan's remarks, made at a news conference here yesterday featuring representatives of several scientific research organizations.

Ingrid Newkirk, national director of People for the Ethical Treatment of Animals, based here, called his comments "absurd" and "antagonistic."

She said animal-research supporters "need to clean up their act generally. Simply to fight for blanket approval of all experiments is transparently absurd."

Other activists said Sullivan's speech, which called animal research "an integral part of mankind's striving for the betterment of humanity," failed to acknowledge cases where use of animals was unnecessary or misplaced.

"Preventable disorders are responsible for more than half the deaths each year in this country, but less than 2 percent of public health dollars go toward prevention," said Neal Barnard, president of the Physician's Committee for Responsible Medicine. "A vast amount of animal experimentation has nothing to do with human health."

The march, scheduled to begin at noon Sunday on the Mall, has been organized by a broad coalition of animal-rights groups and is expected to feature celebrities as diverse as 1960s pop star Grace Slick, horror-movie actress Elvira and actor Christopher Reeve, best known for his roles as "Superman."

While defending activists' right to protest, Sullivan pointed out what he called a "fundamental irony" of the march, saying:

"Without one monumental medical advance achieved through animal research, at least a few of those marching would likely not be able to walk at all. A cure for polio would not have been been found."