Food and Drug Administration Commissioner Scott Gottlieb said he's putting pharmacy chain Walgreens "on notice" for allegedly selling tobacco products to minors.

The agency has already filed formal complaints seeking to block a Walgreens' location in Miami and a Circle K Store in Charleston, South Carolina, from selling cigarettes or cigars for 30 days, citing "repeated violations."

Walgreens, the FDA noted, is currently the top violator among pharmacies that sell tobacco products. Some 22 percent of Walgreens locations inspected by the agency caught employees illegally selling tobacco products to minors, the FDA said in a press release Thursday.

"I will be writing the corporate management of Walgreens and requesting a meeting with them to discuss whether there is a corporate-wide issue related to their stores' non-compliance and put them on notice that the FDA is considering additional enforcement avenues to address their record of violative tobacco sales to youth," Gottlieb said in a statement.

Gottlieb said he's "deeply disturbed that a single pharmacy chain racked up almost 1,800 violations for selling tobacco products to minors across the country."

"I have particular concerns about whether the pharmacy setting is influencing consumer and retailer perceptions around tobacco products in a way that's contributing to these troubling findings," he said.

Walgreens in a statement said it takes this matter "very seriously" and has taken a number of steps to address these concerns, including requiring employees to ask anyone buying tobacco products for identification. The drugstore chain said it will also train all of its store employees on the new requirement and will strengthen disciplinary actions against employees who violate the policy.

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