A conference on tobacco held in Uruguay has recommended that additives used to make cigarettes more appealing to new smokers should be restricted or banned.
Delegates from over 170 countries that have signed a UN tobacco control treaty also said tobacco producers should disclose their products' ingredients.
These guidelines - adopted by consensus - represent the latest public health setback for the tobacco industry.
World Health Organization figures point to big losses of life from tobacco use.
The WHO says that tobacco kills more people than Aids, legal drugs, illegal drugs, road accidents, murder and suicide combined.
It estimates that of the more than six billion people alive today, half a billion will eventually be killed by tobacco.
A spokesman for the WHO's Framework Convention on Tobacco Control, Tarik Jasarevic, told the BBC the industry had lobbied hard against the latest measures.
Mr Jasarevic suggested the delegates wanted to make it harder for the industry to target young people.
"The parties feel that from the point of view of public health, there is no justification to use ingredients that increase the attractiveness of tobacco products, that in turn increase the number of new smokers, especially among young people," he said.
The guidelines would now be used by national governments to draw up legislation, he said. But he added that there was no specific timetable for them to do so.
The head of the International Tobacco Growers Association, Antonio Abrunhosa, criticised the decision.
It allowed governments great leeway in deciding what measures to take, he said.
And he told the AFP news agency that if one popular blend - American - was banned, "it will impact more than 6m producers worldwide".
BBC News
