American teens' use of electronic cigarettes has hit "epidemic proportions," the U.S. Food and Drug Administration said in a statement released Wednesday.
In what it called the "largest coordinated enforcement effort in FDA history," the agency issued written warnings and fines to 1,300 retailers for their role in selling the devices to children.
According to the data cited by the FDA, last year more than 2 million middle school and high school students used the devices, which deliver nicotine in an inhalable form.
In a speech at FDA headquarters, Commissioner Scott Gottlieb said, "The disturbing and accelerating trajectory of use we're seeing in youth and the resulting path to addiction must end.''
Until now, the FDA had eyed e-cigarettes as a powerful tool to help adults break their habit of using conventional tobacco products. But research has found little evidence of such products' effectiveness.
Gottlieb admitted that the agency had neglected to take into account how attractive the flavored products would be to youths.
The commissioner said the FDA would continue to study e-cigarettes as a less harmful alternative for adult smokers, but "that work can't come at the expense of kids.''
The FDA said it was giving the makers of Juul, Vuse, MarkTen XL, Blu and Logic, the five top-selling brands, 60 days to present the agency with a viable plan to prevent vaping among children. If they fail, it could order the products off the market.
The five brands account for more than 97 percent of U.S. sales, according to the FDA.
Critics have long argued that the manufacturers of e-cigarettes are deliberately targeting children by offering their products in sugary flavors.
Gottlieb slammed the e-cigarette makers for approaching the problem of underage use as "a public relations challenge.''
"I'm here to tell them today that this prior approach is over,'' he said.