Vice President Mike Pence used a private AOL email address to conduct state business while he was governor of Indiana.
CNN reported that it was not clear how often he had used the address since he became governor in 2013.
Pence was asked March 2 if there was a similarity with the actions of former Democratic presidential candidate Hillary Clinton, who was frequently criticized during the election campaign for her use of a private email server.
"No, there's no comparison whatsoever between Hillary Clinton's practice of having a private server, mishandling classified information, destroying emails when they were requested by the Congress and by officials," Pence said, according to the BBC.
White House spokeswoman Sarah Sanders agreed.
"He did everything to the letter of the law, he turned all his emails over, unlike Hillary Clinton, who lost at least 30,000, who knows how many more, on her private server," Sanders said, according to CNN.
"He's a governor, which means he wasn't handling classified information like she was," added Sanders.
There have been no allegations that Pence dealt with classified information on his AOL account.
The Vice President also stated he had obeyed the law.
"We have fully complied with all Indiana's laws. We had outside counsel review all of my private email records to identify any emails that ever referenced or mentioned business, state business-related activities," he added, BBC reported.
Pence regularly criticized Clinton during the campaign. On Nov. 2, he told a rally that the "FBI has reopened the investigation in to HRC's private email server. It's a serious matter. Now we commend the FBI in this case for following the facts because in America, no one is above the law," CNN reported.
In one email exchange with his homeland security adviser released to the media, Pence asked for an "update of the investigation in Columbus [Indiana] following the vandalism ... to area churches ... Including the church I grew up in."
His email account was hacked last spring in a fishing scam. All of his contacts received a message saying he had been robbed abroad and urgently needed money.
Republican Gov. Eric Holcomb of Indiana released 30 pages of emails, but has withheld others because they contain sensitive or confidential information.
"It seems Governor Holcomb has chosen to withhold a portion of the public work product Pence sent on private servers, and Indiana Democrats want to know why," the Indiana Democrats said in a statement.
However, Pence spokesman Marc Lotter downplayed the matter.
"Similar to previous governors, during his time as governor of Indiana, Mike Pence maintained a state email account and a personal email," his statement read.