E-cigarettes, which are puffed like a regular cigarette but deliver nicotine by vaporizing liquid rather than burning tobacco, have grown in popularity and some analysts predict the market could outpace conventional cigarettes within a decade.
"We do not yet know the harm that e-cigarettes can cause to adults let alone to children, but we do know they are not risk- free," England's Chief Medical Officer Sally Davies said in a statement.
She added that e-cigarettes can produce toxic chemicals and that variations in the strength of the nicotine solutions between different products meant they could end up being "extremely damaging" to young people's health.
The global market for e-cigarettes was estimated at more than $2 billion last year by market consultant Euromonitor.
Under-18s are already banned from buying conventional cigarettes in Britain. Sunday's announcement included plans to make it illegal for adults to buy regular cigarettes for consumption by under 18s.
Image: Electronic cigarette, via Shutterstock