By Megan Cassela
WASHINGTON (Reuters) - U.S. Defense Secretary Ash Carter said on Thursday his occasional use of a personal email account for work-related matters was "a mistake" that he stopped a few months ago when it became clear to him it was against policy.
Carter, speaking from an American base in Erbil in northern Iraq, told CBS News that he never sent anything classified from his personal account but did occasionally send "administrative" emails to his "immediate staff" from his iPhone.
Carter's use of a private account was first reported by the New York Times on Wednesday.
It follows a controversy surrounding Democratic presidential candidate Hillary Clinton, who used only a personal email account connected to a private server while she was secretary of state from 2009 to 2013. The issue has dogged her campaign for the November 2016 election and sparked an investigation by the Federal Bureau of Investigation.
Carter, who said he does not communicate by email very much, told CBS he had been repeatedly warned to be cautious with his communications after taking the Pentagon's top job in February.
White House spokesman Josh Earnest told reporters that Carter's use of personal email for government business was a "wrong choice" but that it had now been rectified.
"Based on what has been described thus far, it clearly is a mistake because it runs counter to our policy," he said at a news briefing. "The consequences of that mistake at this point, however, do not seem significant."
Senator John McCain, the Republican chairman of the Senate Armed Services Committee, said the committee has requested copies of the emails and will be reviewing them to ensure that sensitive information was not compromised.
"With all the public attention surrounding the improper use of personal email by other administration officials, it is hard to believe that Secretary Carter would exercise the same error in judgment," McCain said in a statement.
Secretary of State John Kerry prefers his government email account for State Department business but occasionally uses a personal account, State Department spokesman John Kirby said.
Government emails sent from his personal account are "appropriately preserved and captured and archived" as required under guidelines implemented after the Clinton email controversy, Kirby said.
"He can't prevent somebody from emailing him if they have (the address for) his private email account, but when that happens we have a process in place ... so that that traffic is appropriately captured," Kirby said.