RICHMOND, VA. - Rotting teeth and gums. Diseased lungs. A sewn-up corpse of a smoker. Cigarette smoke coming out of the tracheotomy hole in a man's neck.

Cigarette packs nationwide will have to carry these macabre images in nine new warning labels that are part of a campaign by the Food and Drug Administration to use fear and disgust to discourage Americans from lighting up.

The labels, announced on Tuesday, represent the biggest change in U.S. cigarette packs in 25 years.

At a time when the drop in the nation's smoking rate has come to a standstill, the government is hoping the in-your-face labels will go further than the current surgeon general warnings toward curbing tobacco use, which is responsible for about 443,000 deaths a year in the United States.

"These labels are frank, honest and powerful depictions of the health risks of smoking," Health and Human Services Secretary Kathleen Sebelius said in a statement.

The FDA estimates the labels will cut the number of smokers by 213,000 in 2013, with smaller additional reductions through 2031.

Other countries such as Canada and Uruguay have used graphic, even grisly, warnings for years, and various studies suggest they spur people to quit. But exactly how effective they are is a matter of debate because the warnings are usually accompanied by other government efforts to stamp out smoking.

"I think it's a great deterrent for kids," said Kristen Polland, 24, of Prattville, Ala. "If you start there, you have won half of the battle."

On the other hand, Rhonda Vanover, 43, of Cincinnati said: "No one is going to stop me -- unless they make it illegal. Cigarettes get me through the day. They are part of my life."

The labels also include images of a smoker wearing an oxygen mask and a mother and baby with smoke swirling nearby. Some images are not graphic at all; one shows a man wearing an "I Quit" T-shirt.

The warnings will take up the entire top half -- both front and back -- of a pack of cigarettes. They must also appear in advertisements and constitute 20 percent of each ad. Cigarette makers will have to run all nine labels on a rotating basis. They have until the fall of 2012 to comply.

The legality of the new labels is already being challenged in a federal lawsuit bought by some of the major tobacco companies, which argue that the warnings will relegate the brand name to the bottom half of the cigarette package, making it difficult or impossible to see.

American Cancer Society CEO John Seffrin said the labels have the potential to "encourage adults to give up their deadly addiction to cigarettes and deter children from starting in the first place."

The introduction of graphic warning labels was required in a 2009 law that, for the first time, gave the federal government authority to regulate tobacco.

Tuesday's announcement follows reviews of scientific literature, public comments and results from an FDA-contracted study of 36 labels proposed last November.

The share of Americans who smoke has fallen dramatically since 1970, from nearly 40 percent to about 20 percent. But the rate has stalled since about 2004, with about 46 million adults smoking cigarettes. It's unclear why it hasn't budged, but some experts have cited tobacco company discount coupons on cigarettes and lack of funding for programs to discourage smoking or to help smokers quit.

In recent years, more than 30 countries or jurisdictions have introduced labels similar to those created by the FDA. The World Health Organization said in a survey done in countries with graphic labels that a majority of smokers noticed the warnings and more than 25 percent said they led them to consider quitting.

In 2000, Canada introduced blunt warning labels that included images of a pregnant woman smoking, a child and parent puffing away and a drooping cigarette to illustrate the risk of impotence from smoking.

Since then, the county's smoking rate has declined from about 26 percent to about 20 percent.