WASHINGTON — Federal health officials took the first step Thursday to slash levels of addictive nicotine in cigarettes, an unprecedented move designed to help smokers quit and prevent future generations from getting hooked.

The Food and Drug Administration floated the proposal last summer, but provided new details in a government filing on the potential impact of drastically cutting nicotine from cigarettes, by as much as 80 percent.

Currently, there are no limits on nicotine, which occurs naturally in tobacco plants. Under law, the FDA can regulate nicotine although it cannot remove it completely.

The FDA’s powers to police the tobacco industry are unique worldwide and the attempt to restrict nicotine would represent a first in global efforts to reduce smoking-related deaths.

Under one scenario, the FDA estimates the U.S. smoking rate could fall as low as 1.4 percent by 2060, down from the 15 percent of adults who smoke now. The agency also calculates that about 5 million more people would quit cigarettes within one year of implementing limits.

The greatest impact, though, would come from preventing young people from ever becoming addicted, they said.

Limiting nicotine “could help keep future generations of kids who experiment with cigarettes from making the deadly progression from experimentation to addiction,” said Mitch Zeller, the head of the FDA’s tobacco center.

The FDA gained authority to regulate ingredients in cigarettes and other tobacco products in 2009.