President Trump’s hesitation to put in place a full ban has become increasingly clear in recent months. In a televised White House meeting in November, he said he was concerned that a full ban would drive people seeking flavors to unsafe, illicit products. And his advisers, including Brad Parscale, his re-election campaign manager, have warned him that a flavor ban would hurt him with his base and could depress turnout in battleground states.

Tobacco and vaping companies have lobbied lawmakers and the White House against banning flavors, including menthol. They have argued that adult smokers need e-cigarette options to help them switch from cigarettes — and that because 35 percent of cigarettes sold are menthol brands, taking menthol flavors off the market would pose a hardship for those smokers trying to quit.

The companies also say that a full flavor ban would put thousands of vape shops out of business.

Industry lobbyists seeking to protect flavors were joined by conservative organizations like Americans for Tax Reform, which opposed regulatory limits that they said would harm the small businesses that manufacture vaping flavors, retailers that sell them and adult consumers of e-cigarettes.

Juul, which dominates the e-cigarette business, has largely stayed out of the fray amid public backlash over its role in the soaring rise of teenage vaping. Facing vociferous and legal opposition from parents, schools and public health experts, the company voluntarily took its fruit- and dessert-flavored products off the market, and has lost business to competitors selling flavors popular with teenagers, like mixed berry, watermelon and mango.

Competitors have also been selling “Juul-alikes,” nicotine pods that fit Juul’s devices in flavors like Strawberry Milk and Peach Madness.

Earlier efforts to restrict sales of flavored e-cigarettes stalled even as the popularity of vaping nicotine grew among millions of young people. The Food and Drug Administration first sought to ban sales of flavors during the Obama administration, but was rebuffed by the White House after fierce lobbying by tobacco companies and retail shops.