The Food and Drug Administration is smoking mad about e-cig sales to kids — and has demanded a sit-down with the Walgreen Co., a “top violator.”

In a letter to the Walgreen Co. on Monday, FDA Commissioner Scott Gottlieb blasted the nation’s largest drug store chain for “repeated violations” of laws prohibiting the sale of tobacco products to minors.

Gottlieb also called for a face-to-face with the company’s “leadership team.”

“These illegal sales must stop,” Gottlieb said before demanding the unusual sit-down. “These statistics about violations at Walgreens retail outlets cannot possibly come as a surprise to corporate leadership,” the FDA chief chided.

The letter, addressed to the Walgreen Co. president of operations Richard Ashworth, was released as part of an FDA initiative to combat the teen vaping “epidemic.”

Since 2010, FDA inspectors have found nearly 1,800 instances in which Walgreens stores failed to follow the law, Gottleib said in the letter.

He called Walgreens “the top violator” among pharmacy chains that sell tobacco products, with 22 percent of its stores that were inspected having illegally sold tobacco products to minors.

The FDA chief gave the retailer 15 days to respond with “a proposed timeline for meeting.”

In an e-mail to The Post, Walgreens claimed to welcome the FDA meeting.

“We have a zero tolerance policy prohibiting the sale of tobacco products to minors, and any employee violating this policy is subject to immediate termination,” it said.

In a separate statement, the FDA’s Gottlieb fingered 14 other national retail chains, in addition to Walgreens, that he said were also in violation of rules against selling tobacco to minors in at least 15 percent of inspected stores.

Six gas station brands were accused of being in violation between 35 percent and 44 percent of all inspected stores: Marathon, Exxon, Sunoco, BP, Citgo and Mobil.

Four chains were found in violation between 25 percent and 34 percent of all inspected stores: Shell, Chevron, Casey’s General Stores and 7-Eleven.

A final five chains, including Walgreens, were said to have failed FDA inspections between 15 percent and 24 percent of the time: Family Dollar, Kroger, Circle K, Walmart.

“We plan to similarly hold them accountable,” Gottlieb said. “The FDA is considering additional enforcement avenues to address high rates of violations.”

In addition, the FDA said it has sent letters to more than 40 companies about whether 50 or more of their products — including flavored varieties of e-cig brands — are being illegally marketed.

“Some of these companies may be attempting to capitalize on the troubling popularity of products like JUUL among kids by illegally selling similar products, ” the agency said.