The Food and Drug Administration on Wednesday declared that teenage use of electronic cigarettes has reached “an epidemic proportion,” and it put makers of the most popular devices on notice that they have just 60 days to prove they can keep their devices away from minors.

The order was part of a sweeping government action that targeted both makers and sellers of e-cigarettes. If Juul Labs and four other major manufacturers fail to halt sales to minors, the agency said, it could remove their flavored products from the market. It also raised the possibility of civil or criminal charges if companies are allowing bulk sales through their websites.

The agency said it was sending warning letters to 1,100 retailers — including 7-Eleven stores, Walgreens, Circle K convenience shops and Shell gas stations — and issued another 131 fines, ranging from $279 to $11,182, for selling e-cigarettes to minors.

Federal law prohibits selling e-cigarettes to anyone under 18. In a briefing with reporters, the F.D.A. commissioner, Dr. Scott Gottlieb, said that more than two million middle and high school students were regular users of e-cigarettes last year.