Officials in San Francisco have proposed the first US ban on electronic cigarettes, amid concerns that the products entice children.

Dennis Herrera, the city attorney, announced on Tuesday that the Californian city was considering a ban until the Food and Drug Administration (FDA) evaluate the effects of e-cigarettes on public health.

Most e-cigarettes contain nicotine, which is addictive and can harm still-developing adolescent brains. In the US, young people are more likely than adults to use e-cigarettes, and manufacturers promote sweet flavours and scents.

"Millions of children are already addicted to e-cigarettes and millions more will follow if we don't act," he said.

Last week the FDA released proposed guidelines, giving companies until 2021 to submit applications for the evaluation. But Mr Herrera said the evaluation should have been carried out before the products went on sale.

Shamann Walton, San Francisco supervisor – a role similar to that of a councillor - introduced legislation banning the sale of e-cigarettes in the city unless they get an FDA review.