The Food and Drug Administration scolded makers of three brands of cigarettes for labels saying they are "natural" or "additive-free". It issued warning letters to Winston maker ITG Brands LLC; Natural American Spirit maker Santa Fe Natural Tobacco Company Inc.; and Nat Sherman maker Sherman's 1400 Broadway N.Y.C. Ltd.

FDA: "The FDA has determined that these products, described as 'natural' and 'additive-free' on their labeling, need an FDA modified risk tobacco product order before they can be legally introduced as such into interstate commerce.”

Congress gave the FDA the authority to regulate tobacco products in 2009 but the agency has moved very slowly and cautiously. It cannot ban products outright. Its first official action didn't come until 2014, when it ordered a company to stop selling cigarette-like products called bidis.

It's also proposed rules restricting sales of electronic cigarettes to adults 18 and over.

Mitch Zeller, director of the FDA's Center for Tobacco Products: "The FDA's job is to ensure tobacco products are not marketed in a way that leads consumers to believe cigarettes with descriptors like 'additive-free' and 'natural' pose fewer health risks than other cigarettes, unless the claims have been scientifically supported. This action is a milestone, and a reminder of how we use the tools of science-based regulation to protect the U.S. public from the harmful effects of tobacco use."

FDA said a company that wants to claim a product is safer than other tobacco products needs to ask the FDA and submit proof of its claim.

"To date, the FDA has not issued any orders permitting the introduction of modified risk tobacco products into interstate commerce," the agency said.

"This is not the first time the government has had to act to prevent the tobacco industry from using its marketing of the term 'additive-free' in ways that mislead the public," the Campaign for Tobacco-Free Kids said in a statement.

"There is no question that terms such as additive-free and natural imply a safer cigarette, as confirmed by consumer research and the industry's own documents, and therefore are health claims covered by the FDA Tobacco Act."