The company expects a slowdown on customer spending for general merchandise in the second half of the year, McMillon said.
Walmart is the largest retailer in the United States, and its move could prompt rivals to bring down prices in these areas.
While lower prices and markdowns are welcome news for shoppers, they mean lower profit for companies. Clothing and general merchandise are more profitable for Walmart than groceries and consumable items.
Walmart in its announcement Monday cut its profit outlook for the second quarter and the remainder of the year.