The World Health Organization says there should be a ban on the use of e-cigarettes indoors and that sales to children should stop.
In a report the health body says there must be no more claims that the devices can help smokers quit - until there is firm evidence to support this.
WHO experts warn the products might pose a threat to adolescents and the foetuses of pregnant women.
But campaigners say regulations must be proportionate.
According to the WHO legal steps need to be taken to end the use of e-cigarettes indoors - both in public spaces and in work places.
And the report focuses on the potential for products to spark wider cigarette use in children.
The health experts call for a ban on advertisements that could encourage children and non-smokers to use the devices.
And they say fruit, candy or alcoholic-drink style flavours should be prohibited too, while the sales of electronic cigarettes from vending machines should be heavily restricted.
The WHO warns exhaled e-cigarette vapour could increase the background air levels of some toxicants and nicotine.
According to the team while e-cigarettes are likely to be less harmful than traditional cigarettes, they may pose threats to adolescents and the foetuses of pregnant women who use these devices.
But some researchers suggest tough regulations may prevent smokers having access to products that are potentially less harmful than conventional cigarettes.
A spokesman for the British American Tobacco company said: "We have always said that given nicotine is addictive, minimum age laws of 18 for the sale of e-cigarettes should be introduced.
"However, if overly restrictive regulations are introduced hampering innovation or adult usage, then this could simply stifle the growth of new products and prevent smokers from being aware of and having access to them - this can only be bad thing for public health."