A new law sets the nationwide minimum age to buy tobacco products at 21.
The law applies to cigarettes, cigars, e-cigarettes, and vaping devices that heat a liquid containing nicotine. Selling them to people under 21 is now illegal across the country.
The change took effect immediately after President Donald Trump signed a recent spending bill that included the age increase.
About a third of states already had restricted tobacco sales to those 21 and older. North Carolina's minimum age had been 18. The state is the nation's largest tobacco producer.
The move caught some retailers off guard. The U.S. Food and Drug Administration says it will provide additional details as they become available.