The United States Surgeon General, Dr. Vivek Murthy, announced on Monday that he would push for a warning label on social media platforms advising parents that using the platforms might damage adolescents’ mental health.

Warning labels — like those that appear on tobacco and alcohol products — are one of the most powerful tools available to the nation’s top health official, but Dr. Murthy cannot unilaterally require them; the action requires approval by Congress. No such legislation has yet been introduced in either chamber.

A warning label would send a powerful message to parents “that social media has not been proved safe,” Dr. Murthy wrote in an essay published in The New York Times opinion section on Monday.

In his essay, he cast the effects of social media on children and teenagers as a public health risk on par with road fatalities or contaminated food.

“Why is it that we have failed to respond to the harms of social media when they are no less urgent or widespread than those posed by unsafe cars, planes or food?” Dr. Murthy wrote. “These harms are not a failure of willpower and parenting; they are the consequence of unleashing powerful technology without adequate safety measures, transparency or accountability.”

Dr. Murthy pointed to research that showed that teens who spent more than three hours a day on social media faced a significantly higher risk of mental health problems, and that 46 percent of adolescents said social media made them feel worse about their bodies.