FDA Commissioner Scott Gottlieb said that he plans to contact the companies in question and ask them about their policies regarding tobacco sales and where they plan to improve, CNBC reports.

The companies have been found to sell tobacco products to minors more than 15% of the time. One of the 15 major offenders was Walgreens, where 22% of its locations were found to be selling tobacco products to underage customers.

Gottlieb reportedly contacted Walgreens and asked for a meeting with its top management to discuss the issue. News that Walgreens was the top offended actually broke last month at which time Walgreens said it planned to institute a policy where anyone purchasing tobacco products would need to provide an ID regardless of their perceived age.

Below are all 15 of the named companies along with their violation rates:

Violation Rates Between 35-44 Percent of All Inspected Stores

• Marathon
• Exxon
• Sunoco
• BP
• Citgo
• Mobil

Violation Rates Between 25-34 Percent of All Inspected Stores

• Shell
• Chevron
• Casey’s General Stores
• 7-Eleven

Violation Rates Between 15-24 Percent of All Inspected Stores

• Family Dollar
• Kroger
• Walgreens
• Circle K
• Wal-Mart

“Retailers are on the frontlines of these efforts to reduce the health consequences of tobacco use and nicotine dependence,” Gottlieb said in a statement on Monday. “Walgreens and other retail chains should take seriously not only their legal obligations but also the substantial public health importance of preventing tobacco product sales to minors at their stores.”

The FDA’s complaint about Walgreens, in particular, involved more than 1,800 citations for selling tobacco to minors. The FDA could potentially force offending retailers to temporarily stop selling tobacco products. Circle K stores were also named in the FDA’s initial complaint.