US announces ban on e-cigarettes for under-18s
The US government has unveiled new federal rules that include a ban on the sale of e-cigarettes to people aged under 18.
The Food and Drug Administration (FDA) will also require manufacturers to submit products to the agency for review.
Cigars, pipe tobacco and hookah tobacco are also subject to the new rules.
On Wednesday, California introduced new anti-smoking legislation that also regulates e-cigarettes.
E-cigarettes are battery-operated devices that turn flavoured nicotine liquid into an inhalable vapour.
They lack the chemicals and tars of tobacco and are widely used by smokers trying to kick the habit. However, the nicotine is addictive.
In a statement, US secretary of health and human services Sylvia Burwell said the announcement was "an important step in the fight for a tobacco-free generation".
"It will help us catch up with changes in the marketplace, put into place rules that protect our kids and give adults information they need to make informed decisions," she said.
The FDA said that a recent survey showed e-cigarette use among high school students had risen from 1.5% in 2011 to 16% in 2015 and that the use of hookah tobacco had also increased significantly.
It said the new rules, which come into effect in 90 days, will require retailers to ask buyers for proof of age and will ban the sale of the products in vending machines. Free samples will also be barred.
Public health advocates welcomed the news.
"Ending the tobacco epidemic is more urgent than ever, and can only happen if the FDA acts aggressively and broadly to protect all Americans from all tobacco products," said Harold Wimmer, president of the American Lung Association.
In California, Democratic Governor Jerry Brown signed a total of five bills to restrict tobacco use in various ways, including regulating e-cigarettes and expanding funds for anti-smoking programmes.
The rules raise the legal age for buying tobacco products in the state from 18 to 21, except for active military personnel.
Electronic cigarettes, like traditional ones, will be banned in public spaces across the state.