WASHINGTON — President Trump on Thursday directed the Department of Health and Human Services to declare the opioid crisis a public health emergency, taking long-anticipated action to address a rapidly escalating epidemic of drug use.

But even as he vowed to alleviate the scourge of drug addiction and abuse that has swept the country — a priority that resonated strongly with the working-class voters who supported his presidential campaign — Mr. Trump fell short of fulfilling his promise in August to declare “a national emergency” on opioids, which would have prompted the rapid allocation of federal funding to address the issue.

His directive does not on its own release any additional funds to deal with a drug crisis that claimed more than 59,000 lives in 2016, and the president did not request any, although his aides said he would soon do so. And he made little mention of the need for the rapid and costly expansion of medical treatment that public health specialists, including some in his own administration, argue is crucial to addressing the epidemic.

“No part of our society — not young or old, rich or poor, urban or rural — has been spared this plague of drug addiction and this horrible, horrible situation that’s taken place with opioids,” Mr. Trump said during an elaborate and emotional ceremony in the East Room of the White House, attended by families affected by opioid abuse, members of Congress and administration officials. “This epidemic is a national health emergency.”