MANILA — President Rodrigo Duterte, who has overseen a deadly campaign to eradicate drug use in the Philippines, has now ordered a strict public ban on smoking and called on citizens to help the local authorities apprehend smokers.

The executive order, signed this week and made public on Thursday, forbids the use of tobacco, including electronic cigarettes, in all public spaces, even sidewalks. It also prohibits anyone under 18 from “using, selling or buying cigarettes or tobacco products.”

More than a quarter of Filipinos smoke, according to a 2015 World Health Organization report, including 11 percent of minors.

The nationwide measure, known as Executive Order 26, is similar to the near universal smoking ban Mr. Duterte put in place in Davao City in 2002, when he was the city’s mayor. A former smoker, Mr. Duterte quit cigarettes and drinking decades ago, when he was found to have two rare conditions, Barrett’s esophagus and Buerger’s disease.