The U.S. Department of Justice's antitrust chief on Tuesday defended his aggressive stance against large corporations seeking to assert their market dominance, saying his duty is to the American people who are protected by law from the anti-competitive actions of the companies they enrich.

"My name is Jonathan Kanter and I represent the people of the United States of America," he said at the Anti-Monopoly Summit sponsored by the American Economic Liberties Project. He added that the Antitrust Division he leads has built an "unprecedented record of action" in challenging what he called anti-competitive mergers and monopolizing activities.