A top U.S. regulator wants to meet with Walgreens leaders to discuss whether the drugstore chain has a problem with illegal tobacco sales to minors.

Scott Gottlieb of the Food and Drug Administration said Monday Walgreens is a top violator among drugstores that sell tobacco products including cigarettes, smokeless tobacco and e-cigarettes. He says inspectors have found nearly 1,800 instances since 2010 in which one of the company’s stores violated the law.

Deerfield, Illinois-based Walgreens Boots Alliance Inc. runs more than 9,500 U.S. drugstores. Spokesman Jim Cohn says the company welcomes a meeting with the FDA. He says Walgreens prohibits tobacco sales to minors, and employees who violate that policy can be fired immediately.

Walgreens rival CVS Health Corp. quit selling tobacco in its stores several years ago.