Michael Horn, Volkswagen's president and CEO in the U.S., apologized to members of the U.S. Congress on Oct. 8 for selling cars that included a software cheat designed to defeat federal diesel emissions testing.

Horn called the scandal "deeply troubling" during testimony in front of the House Committee on Energy and Commerce Subcommittee on Oversight and Investigations. Horn promised full cooperation with several pending investigations.

"Let me be clear, we at Volkswagen take full responsibility for our actions and we are working with all relevant authorities in a cooperative way," Horn said. "I am here to offer the commitment of Volkswagen AG to work with this Committee to understand what happened, and how we will move forward. EPA, CARB, the U.S. Department of Justice, state attorneys General, as well as other authorities, are fulfilling their duties to investigate this matter."

Read Horn's full testimony here.