U.S. regulators are hitting the brakes on plans to force tobacco companies to drastically reduce addictive nicotine in cigarettes, retreating on an ambitious public-health initiative that comes amid increasing worry about nicotine use among young people.

The Department of Health and Human Services has dropped a proposal unveiled two years ago to cut the level of nicotine in cigarettes to nonaddictive levels, according to a regulatory document published on Wednesday.

Abandoning the plan, which almost certainly would have meant a sharp reduction in tobacco sales, would be a major victory for the tobacco industry. The move also comes at a time when public debate is focused on the potential for e-cigarettes to create a new generation of nicotine addicts.

Representatives for the Food and Drug Administration and the Department of Health and Human Services didn't immediately respond to requests for comment. Shares of Altria Group Inc., the maker of Marlboro cigarettes, rose 3.5% at 11:49 a.m. in New York. Philip Morris International Inc. rose 1.6%.

In a notice posted on a government website earlier this year as part of the Food and Drug Administration's near-term regulatory goals, the agency said that the policy "would have significant public health benefits for youth, young adults, and adults, as well as potentially vast economic benefits."

That goal, once included as part of the "unified agenda" of regulations the government is working on, is no longer listed on the website, which was updated Wednesday as part of a semiannual review.

In 2017, then-FDA Commissioner Scott Gottlieb said he wanted to reduce nicotine levels in cigarettes and other burnt tobacco to near-zero. Almost half a million people in the U.S. die each year from tobacco-related causes, according to the Centers for Disease Control and Prevention, and the move was hailed at the time as a potentially monumental public-health decision.

It also shocked Wall Street, sending stocks of tobacco giants plunging as investors reconsidered whether people would bother smoking a cigarette without the addictive chemical. The move was paired with a decision — later reversed — to give e-cigarette makers extra time to keep their products on the market without regulation.

Gottlieb left the FDA before the nicotine policy could be seen through. Altria later bought a $12.8 billion stake in e-cigarette market leader Juul Labs Inc., a hedge against declining smoking rates.

The update to the U.S. regulatory agenda was published on the same morning that a Senate panel was considering the nomination of Texas oncologist Stephen Hahn to be the new head of the FDA.

The Trump administration had vowed tough curbs on flavored vaping products in September. Since then, however, the president has signaled that any effort to clear the market of flavored products that appeal to young people is on hold.

The FDA's oversight of the tobacco industry was the product of a pitched political battle that began in the 1990s and culminated in a 2009 law giving the agency oversight of cigarettes and other smokeless products.

Recently, some administration officials have questioned the FDA's role in regulating tobacco. Joe Grogan, the head of the White House Domestic Policy Council, earlier this month called the FDA's regulation of tobacco "a huge waste of time" and said the agency should focus on pharmaceuticals.