WASHINGTON — Nearly four years after it began regulating cigarettes, the Food and Drug Administration is poised to extend its reach to a broader range of tobacco products. At the top of that list: cigars, which have experienced a boom in recent years even as cigarette sales have declined, in part because of growing popularity among young people. 

Anti-tobacco advocates and industry representatives widely expect the agency to require changes in the marketing and manufacturing of cigars. But the central question remains: What kind of cigars will the FDA target, and how? 

On one end of the spectrum are the hand-rolled Cohibas and Arturo Fuentes that stock the humidors of high-end cigar shops and are favored by aficionados who don’t blink at paying top dollar. On the other are the convenience-store brands that appeal primarily to young smokers, such as 59-cent blueberry Swisher Sweets, peach-flavored White Owl Cigarillos, Phillies Blunts Sour Apple and menthol Cheyenne “little cigars” that are barely distinguishable from cigarettes. 

Public health experts and some anti-tobacco lawmakers are pressing the FDA to regulate all cigars — but, in fact, they mostly worry about the inexpensive, flavored varieties that have proliferated in recent years. Such cigars “are marketed aggressively and have resulted in high school kids and young adults being twice as likely as their older counterparts to be cigar smokers,” the Campaign for Tobacco-Free Kids said in a recent report. 

Meanwhile, makers of “premium cigars” have been lobbying intensely in an effort to avoid being lumped in with the candy- and fruit-flavored, corner-store varieties. A bill on Capitol Hill, co-sponsored by dozens of lawmakers, would keep carefully defined “traditional large and premium” cigars out of the FDA’s reach, although its prospects remain uncertain. 

“You don’t see a teenager with a $15 premium cigar sticking out of his mouth, standing on the corner,” said Bill Spann, president of the International Premium Cigar & Retailers Association. “Nobody’s ducking outside for a 15-minute cigar break. Nobody’s smoking two boxes of cigars a day. You don’t inhale them. And they are not marketed to, desired by or affordable to underage youth.” 

The industry’s main trade association, the Cigar Association of America, which represents all kinds of cigar manufacturers, is pushing a simple message: One-size-fits-all regulation won’t work. 

“All our products are different, so you should look at all of them differently,” said Craig Williamson, president of the cigar group. 

The 2009 law that gave the FDA power to regulate cigarettes and several other types of tobacco also authorized it to broaden its jurisdiction to include other products, such as cigars, pipe tobacco and e-cigarettes. Late last year, the FDA said it would issue a proposal by April. 

In the interim, cigarmakers have begun to brace for their first brush with government regulation and the changes that might bring. “It’s something we’ve been planning for,” said David Sylvia, a spokesman for Altria Group, the parent company of John Middleton, which manufactures the popular Black & Mild cigar brand and a variety of pipe tobaccos. 

The FDA has yet to outline its plans, leaving plenty of speculation about whether the agency will regulate different cigars differently — without creating loopholes. 

“If they can’t figure out a way to keep this thing from being gamed, then they basically shouldn’t make any exemptions,” said Richard Daynard, a Northeastern University law professor and president of its Public Health Advocacy Institute. 

The 2009 tobacco control law banned candy and fruit flavorings in cigarettes, which had been shown to disproportionately appeal to young people. Some companies reacted by making small changes in the products, such as adding tobacco to the wrapper to help them meet the legal definition of cigars. 

Another 2009 federal law put in place sharp tax increases on cigarettes and small cigars but spared larger cigars. In response, companies added weight to their products to qualify for the lower taxes. 

Even as cigarette smoking decreased between 2000 and 2011, consumption of loose tobacco and cigars grew 123 percent, according to the Centers for Disease Control and Prevention. The CDC found that tax disparities prompted many smokers to switch from cigarettes to other products such as cigars. 

In at least six states, including Maryland, youth cigar smoking now equals or surpasses cigarette smoking, according to numbers compiled by the Campaign for Tobacco-Free Kids — a figure the group says underscores the urgency of FDA regulation. 

Spann hopes that the FDA at least decides to exclude the small companies and storefronts that make and sell premium cigars. Or that if the agency doesn’t, Congress will. 

“There are 85,000 Americans working in or around the premium cigar market in America,” he said. “The government should be helping them, not trying to regulate them out of business.” 

Matthew Myers, president of the Campaign for Tobacco-Free Kids, said there is no evidence that the FDA intends to impose a host of onerous, unnecessary regulations on mom-and-pop, large cigar manufacturers. “They have bigger fights to fight,” he said.