U.S. health officials plan to ask for a meeting with top management from Walgreens Boots Alliance to discuss what they said was a pattern of illegal tobacco sales to minors at the pharmacy giant’s stores.

The Food and Drug Administration said Thursday that it would block a Walgreens store in Miami from selling tobacco products for 30 days. The agency said 22 percent of the Walgreens stores it had inspected had illegally sold tobacco products to minors.

The FDA inspected 6,350 Walgreens stores, said Michael Felberbaum, an agency spokesman. Walgreens has received more than 1,550 warning letters from the FDA and has incurred 240 financial penalties since 2010 for selling tobacco to minors, he said.

“Walgreens is currently the top violator among pharmacies that sell tobacco products,” the agency said in a statement.

FDA Commissioner Scott Gottlieb said the agency is considering additional enforcement action against Walgreens.

Gottlieb said he was particularly concerned about how selling cigarettes in a pharmacy setting influenced consumer perceptions of the health effects of smoking. CVS Health, the giant drugstore chain that recently merged with health insurer Aetna, stopped selling tobacco products in 2014.

In December, Walgreens posted mediocre quarterly results and said it would cut costs. While prescriptions increased in its pharmacies, same-store retail sales, which include items such as shampoo and beauty products as well as tobacco, fell 3.2 percent in the U.S. Walgreens blamed the decline in part on de-emphasizing tobacco.

Major tobacco companies have been betting on e-cigarettes as a way to offset a decline in sales of cigarettes and other tobacco products. Marlboro maker Altria Group spent $13 billion last year to take a 35 percent stake in Juul Labs, which makes vaping devices that are popular with young users.