Democratic 2020 U.S. presidential candidate and former South Bend Mayor Pete Buttigieg speaks to a man after a campaign town hall meeting at the Tama County Nature Center in Toledo, Iowa, U.S., January 15, 2020. REUTERS/Shannon Stapleton

WASHINGTON (Reuters) - The top cybersecurity official with the presidential campaign of South Bend, Indiana Mayor Pete Buttigieg told Reuters on Wednesday that he has resigned, citing philosophical differences with the campaign over information security.

Mick Baccio, who was the highest-ranking cybersecurity official of any of the ongoing U.S. presidential campaigns, said he quit earlier this month.

He left because of a “fundamental philosophical difference with campaign management regarding the architecture and scope of the information security program.”

The campaign confirmed his resignation and added that they have retained a new security firm.

Baccio joined the Buttigieg campaign in July 2019 to build a comprehensive cybersecurity program that could protect staffers from cyberattacks and secure their systems. He previously served as a White House cybersecurity professional.

It is not common for political campaigns to employee full-time cybersecurity experts. But following Russian cyberattacks against the 2016 U.S. presidential election, politicians have grown more concerned about cyber threats.