WASHINGTON • Faced with a worsening epidemic of teenage vaping and a mysterious illness stalking users of cigarette alternatives, the Trump administration has promised to ratchet up its oversight of a burgeoning but increasingly troubled industry.

US President Donald Trump said on Wednesday that vaping had become an urgent public health concern, "specifically with respect to children".

Health and Human Services Secretary Alex Azar told reporters that five million children said they have vaped this year - a steep jump from the 3.6 million who said they had used e-cigarettes last year.

"We may very well have to do something very, very strong about it," Mr Trump, flanked by Mr Azar and Acting Food and Drug Administration (FDA) commissioner Norman Sharpless, told reporters in the White House Oval Office.

Vaping has been touted as a safe and effective way for adult smokers to quit their cigarette habits, and investors have poured billions of dollars into the business.

But a combination of candy-like flavourings, sleek electronic devices and social media marketing has also lured children. The jarring rate at which teens have adopted devices like the compact, easy-to-hide one produced by Juul Labs has made health officials around the United States snap to attention.

Additionally, vaping appears to be making more people sick. A mysterious lung disease linked to inhaling vapour has killed at least six people and injured hundreds more across the US this summer. State and federal investigators are racing to identify the precise cause of the ailment.

Mr Azar said the FDA would issue guidance in the coming weeks to clamp down on the sale of flavoured vaping products.

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