As a senator, Secretary of State John Kerry John Forbes KerryThe Memo: Warning signs flash for Trump on debates Divided country, divided church TV ads favored Biden 2-1 in past month MORE sent at least one email to Hillary Clinton from his personal account that has now been classified as secret, the State Department confirmed on Tuesday.

The largely redacted May 19, 2011, email from Kerry — then the chairman of the Foreign Relations Committee — “was sent from a non-official account,” State Department spokesman John Kirby said on Tuesday.

ADVERTISEMENT

That account, Kirby added “is no longer active.”

The message referenced India, Afghanistan and Pakistan, and was classified for containing information about foreign governments and U.S. foreign relations.

“We all know this will be a troubled relationship because that is it’s [sic] nature,” he wrote in one unredacted section. “But there are real possibilities at this moment to put options to the test.”

Kerry’s email was classified at the “secret” level, which is a higher level than “confidential” but lower than “top secret”

A note at the bottom of the message indicates that it was sent from Kerry’s iPad.

Key Obama administration officials have struggled with stories about their use of personal email accounts for official business, but none more than Clinton, the former secretary of State and current Democratic presidential front-runner.

Clinton’s use of a personal email address throughout her tenure at the State Department has made her a target of criticism from many Republicans and transparency advocates. Critics of the practice worry that using an unsecure account to send secret information could jeopardize classified information.

More than 1,300 of Clinton’s emails have been classified at some level. However, the State Department has maintained that the emails were not classified at the time that they were sent, but instead were given the extra protections retroactively.

Kerry currently uses a State Department-issued email address, Kirby said.

On Tuesday, the head of the Senate Judiciary Committee expanded his probe into the how Obama administration officials used personal email accounts, demanding answers from Defense Secretary Ashton Carter. Cater used a personal email account for months after he took the reins at the Pentagon last year.