FRANKFURT — Volkswagen said on Sunday that it would halt sales of cars in the United States equipped with the kind of diesel motors that had led regulators to accuse the German company of illegally installing software to evade standards for reducing smog.

John Schilling, a Volkswagen spokesman, said that the company would stop selling 2015 and 2016 Volkswagen and Audi models equipped with 4-cylinder turbo diesel engines, which the company has marketed as “clean diesel.” The company will also stop selling used cars that have the engines, Mr. Schilling said.

He said he did not know how many models would be stuck on dealer lots as a result of the decision. Earlier this month, Volkswagen had said that 23 percent of new cars sold in August in the United States were diesels, or 7,400 vehicles.

The confirmation of the halt in sales came on the same day that Martin Winterkorn, the chief executive of Volkswagen, apologized for conduct that prompted the Environmental Protection Agency to order Volkswagen to recall nearly half a million vehicles.