NEW YORK (AP) — Walmart said Wednesday that it will raise the minimum age to buy tobacco products and e-cigarettes at its U.S. stores to 21 amid growing pressure from regulators to cut tobacco sales and use among minors.

The world's largest retailer also said it will also stop selling fruit and dessert flavored e-cigarettes, which critics say can hook teenagers on vaping.

The new rules will take effect in July at all its 5,300 U.S. stores, including its Sam's Club warehouse locations. Previously, Walmart's minimum purchase age was 18, aside from a number of states where the legal age is 21.

Earlier this year, the Food and Drug Administration put Walmart and 14 other retailers on notice for selling tobacco products to kids. Another retailer on the list, drugstore operator Walgreens, said last month that it would increase its minimum age for tobacco sales to 21 in September.

In a letter to the FDA Wednesday, Walmart said it will conduct its own tests this year to make sure minors can't buy tobacco products at its stores. The company said it will retrain workers that fail its tests.

"Even a single sale to a minor is one too many, and we take seriously our responsibilities in this regard," said John Scudder, Walmart's chief compliance and ethics officer, in a blog post Wednesday.