FDA says menthol smokes 'worse' than normal cigarettes
US regulators have said menthol cigarettes are more harmful than other cigarettes, but stopped short of limiting their sale.
The Food and Drug Administration (FDA) said it would seek consultation on possible restrictions for the products.
The agency said that while mint-flavoured cigarettes may be just as toxic as others, it was easier to start smoking them and harder to quit.
Menthol cigarettes are one of the few growing areas of the tobacco industry.
The FDA has commissioned further research into the subject.
It is inviting input from the health community, tobacco industry and members of the public about the products.
"Menthol cigarettes pose a public health risk above that seen with non-menthol cigarettes," said the preliminary results of the FDA's study.
It also found the cooling and anaesthetic qualities of the menthol made them less harsh - and more appealing - to smokers.
The report's conclusions echoed some of the findings of an earlier review from 2011, which suggested that a ban on menthol cigarettes would benefit public health.
But the tobacco industry has said that menthol cigarettes do not need to be subject to different regulations from normal cigarettes.
A group of former health officials, including two cabinet secretaries from the Carter and Bush Senior administrations, denounced the FDA's inaction.
"The failure of this administration to act undermines the public health and is particularly harmful to vulnerable young Americans and African-Americans," they said in a joint statement.
According to an earlier study from the US Department of Health only about 25% of white smokers choose menthol cigarettes, while more than 70% of African-American smokers use them.