The FDA vs. Juul feud continues as FDA Commissioner Scott Gottlieb has arranged to meet the companies in Washington to talk about how the merger could help combat teen vaping, and what implications it will have on preventative measures in general.

"After Altria's (MO  ) acquisition of a 35% ownership interest in JUUL Labs, Inc., your newly announced plans with JUUL contradict the commitments you made to the FDA," Gottlieb wrote in a heated letter addressed to Altria chairman Howard A. Willard III.

"When we meet, Altria should be prepared to explain how this acquisition affects the full range of representations you made to the FDA and the public regarding your plans to stop marketing e-cigarettes and to address the crisis of youth use of e-cigarettes," it read.

In September, Gottlieb stated that he wanted the five largest e-cig manufacturers to submit legitimate, constructive plans detailing how they planned to deal with the teen vaping situation given their role in the vaping epidemic.

Altria was the first of these companies to claim cooperation, pledging to pull its own e-cigs from retail shelves and admitting that fruity flavors strategically attracted a younger consumer base to harmful products. Juul voluntarily shut down its social media accounts, pledged to change its marketing tactics, and discontinued several of its fruit and candy flavors out of retail stores globally.

"I'm concerned," Gottlieb said in an interview. "Did something change? Do they have new data? Do they have a new understanding? Because they just made a very big commitment to support the expansion of pod-based products, which they said contributes to the youth epidemic."

"If the rates of youth use continue to increase sharply we're going to have to take additional steps - there's no question about that," he continued.

Given that the FDA has the power to remove Juul products from the market, Altria and Juul will have to carefully negotiate their market positioning at the upcoming meeting. They'll have to play their cards right, so as to avoid being completely pushed out of stores.

"Both Altria and Juul have taken significant steps that exceed what others in the industry have done," said Altria spokesman Steven Callahan in a statement.