CNN  — 

First lady Melania Trump on Monday aired her concern over the growing dangers associated with e-cigarettes and use of them by children.

“I am deeply concerned about the growing epidemic of e-cigarette use in our children. We need to do all we can to protect the public from tobacco-related disease and death, and prevent e-cigarettes from becoming an on-ramp to nicotine addiction for a generation of youth,” the first lady tweeted.

The US Food and Drug Administration sent a warning letter on Monday to Juul, the leading manufacturer of e-cigarettes, specifically addressing the company’s marketing tactics, which have stated e-cigarettes are a safer alternative to regular cigarettes. Additionally, there is concern that Juul’s message has been aimed directly at underage consumers.

“Regardless of where products like e-cigarettes fall on the continuum of tobacco product risk, the law is clear that, before marketing tobacco products for reduced risk, companies must demonstrate with scientific evidence that their specific product does in fact pose less risk or is less harmful,” acting FDA Commissioner Dr. Ned Sharpless said in a statement about its warning to Juul, which has been given 15 days to respond to the FDA’s letter.

“JUUL has ignored the law, and very concerningly, has made some of these statements in school to our nation’s youth,” Sharpless wrote.

The first lady’s “Be Best” initiative is centered on helping children, and one of its three pillars targets the health and well-being of kids.

There has been a dramatic rise in the number of children and teenagers using e-cigarettes since products have become more available, and Juul’s advertising and marketing campaigns have ramped up. The US Centers for Disease Control and Prevention is working in tandem with the FDA to monitor the dangers associated with e-cigarette use, which in recent weeks has been linked to severe health concerns.

On Friday, US health officials announced they is now aware of at least 450 possible cases of severe lung disease that could be caused by vaping across 33 states. Additionally, There have been at least five deaths across five states – one each in Illinois, Oregon, Minnesota, Indiana and California – linked to the illnesses.

“We’ve also put the industry on notice: If the disturbing rise in youth e-cigarette use continues, especially through the use of flavors that appeal to kids, we’ll take even more aggressive action,” Sharpless wrote in his Monday letter to Juul, whose vape products use many sweet flavorings attractive to young people, including watermelon, grape and strawberry lemonade.

The first lady previously addressed e-cigarette use during a youth leadership forum in February, which focused on opioid abuse in young people.

Trump was asked about the rise of e-cigarettes and kids.

“It’s like a whole box of cigarettes,” she said, noting that she and other parents are concerned children don’t understand the full danger of e-cigarettes. “(It is) another issue that we need to deal with.”