In recent months, the F.D.A. has mounted an increasingly aggressive campaign against the major manufacturers of vaping products that appeal to young people, focusing particularly on Juul. The company’s sleek device (nicknamed the iPhone of e-cigarettes) resembles a flash drive and comes with flavor pods like crème and mango, leading public health officials to criticize the company and others for appearing to market directly to teenagers, who are especially vulnerable to nicotine addiction.

E-cigarettes were originally developed to help smokers quit by giving them a way to satisfy their nicotine cravings without the tar and deadly carcinogens that come with burning tobacco.

“Our intent was never to have youth use Juul,” said Kevin Burns, chief executive of Juul Labs in a statement emailed to reporters. “But intent is not enough. The numbers are what matter and the numbers tell us underage use of e-cigarettes is a problem.”

But critics and public health advocates said the company had no choice, especially after the F.D.A. seized documents related to marketing strategies from the company’s headquarters last month, and while some states were investigating whether its tactics were directly aimed at minors.

Caroline Renzulli, a spokeswoman for the Campaign for Tobacco-Free Kids, called Juul’s announcement too little too late. “Juul’s social media marketing fueled its popularity with kids,” she said. “Now that it has captured 75 percent of the e-cigarette market, Juul no longer needs to do social media marketing because its young customers are doing it for them.”