The U.S. Surgeon General's office says more must be done to keep young Americans from using tobacco.

Nearly one in five teenagers smokes, according to a new government report.

And although that rate is down from previous decades, the rate is slowing, drawing new concern that smoking bans and increased taxes on tobacco products may be necessary.

Learn more about the Surgeon General's campaign to stop teenage smoking here.

"In order to end this epidemic, we need to focus on where we can prevent it and where we can see the most effect, and that's with young people," Surgeon General Regina Benjamin said.

"We want to make our next generation tobacco-free, and I think we can," she said.

Studies show that more than 80 percent of smokers start by age 18. The 920-page report also analyzed cigarette marketing to young people. Nearly $10 billion was spent by tobacco companies in 2008 for advertising.

To raise awareness on the dangers and prevalence of smoking, the Surgeon General's office is launching a contest for young people to submit videos on the report's findings for a chance to win cash prizes.