More high school kids are smoking cigarettes as vaping surges, reversing a two-decade-long decline.

This year, 8.1 percent of high school students reported smoking cigarettes, up from 7.6 percent last year, according to federal health officials, who asked not to be named because the data haven't been publicly released. The increase is not statistically significant, but it is likely to fuel growing controversy about teen use of e-cigarettes.

Preliminary data from the Centers for Disease Control and Prevention's annual National Youth Tobacco Survey also show e-cigarette use among high school kids surging by about 77 percent, numbers so staggering that Food and Drug Administration Commissioner Scott Gottlieb is labeling youth use of e-cigarettes an "epidemic." The complete data set, which was reviewed by federal health officials, is expected to be released later this year.

Teen smoking rates have plummeted since peaking in 1997 when 36.4 percent of high school students surveyed in the CDC's Youth Risk Behavior Survey said they regularly smoked cigarettes. In 2015, the National Youth Tobacco Survey identified a slight uptick — up to 9.3 percent from 9.2 percent in 2014 — before falling again to 8 percent in 2016.

Critics have warned a surge in e-cigarette use may cause nicotine-addicted kids to migrate to conventional cigarettes. The new data suggest this may be happening.