That's just one plank in the administration's new plan to curb youth vaping, Trump told reporters.
"We have to take care of our kids, most importantly, so we're going to have an age limit of 21 or so," the Associated Press reported.
The White House's proposed move is not the first in the United States: About a third of states have already raised their sales age to 21. But federal law still puts the age at 18.
Back in September, President Trump announced that the White House would propose a ban on all flavored e-cigarette products as well. Flavored vapes are thought to be especially attractive to kids and teens.
However, the absence of such an announcement on Friday has some experts worried that Trump might not come through with that move, the AP said.
Trump's statement to reporters was somewhat vague.
"We're talking about the age, we're talking about flavors, we're also talking about keeping people working - there are some pretty good aspects," he said.
And in a separate White House event on Friday, Trump adviser Joe Grogan seemed to offer a softer stance on vaping.
He called e-cigarettes are "a viable alternative to combustible cigarettes," the AP reported. "We really want to make sure we're data-driven on this and striking the right balance between adult choice and protecting kids," Grogan said.
Kids are being harmed, however: The latest federal data shows 1 in every 4 high schoolers now vapes.
On Thursday, leading vaping products maker Juul announced it was adding the highly popular mint flavor to its list of flavored e-cigarettes withdrawn from the market. According to the AP, that would leave just two Juul flavors to choose from tobacco and menthol.
In Congress, Senate Majority Leader Mitch McConnell recently introduced a "Tobacco 21" law to raise the age needed to buy traditional or e-cigarettes to 21. The bill is expected to have bipartisan support.
In the meantime, more than 2,000 people have been hospitalized with a severe lung illness tied to vaping. A study released Friday in the CDC journal Morbidity & Mortality Weekly Report suggests that one additive, vitamin E acetate, might be largely to blame.