Former Defense Secretary Chuck Hagel has accused unnamed White House aides of attempting to "destroy" him personally by smearing his reputation during his final days of office.

Hagel said in a new interview with Foreign Policy that he doesn't know why anonymous administration officials would backstab him by planting stories in the press describing why President Barack Obama asked him to step down after he had already handed in his resignation.

While Hagel, 69, didn't name any specific officials in his interview, his criticism seems to be directed toward Obama's national security adviser, Susan Rice, and some of her staff, whom Hagel "frequently butted heads" with over Syrian policy and U.S. military prisons at Guantanamo Bay, according to Foreign Policy. 

"They already had my resignation, so what was the point of just continuing to try to destroy me?" Hagel asked in the interview, speaking for the first time about his treatment by the Obama administration.

"I don't know what the purpose was. To this day, I'm still mystified by that. But I move forward. I'm proud of my service," he said, adding that he "would have preferred that my days as defense secretary did not end that way."

One obvious example cited by Foreign Policy is an article from The New York Times from November 2014, in which anonymous administration officials criticized Hagel for being mostly silent in meetings and thwarting Obama's pledge to close Guantanamo by claiming that releasing detainees posed security risks. In once instance, officials told the Times that Hagel "pulled back from plans to repatriate four Afghans who had been approved for transfer, a decision that annoyed Ms. Rice."

Hagel and the administration also clashed over the president's Syria policy, with Hagel telling Foreign Policy that there was "no question in my mind" that Obama's decision in 2013 to not attack Syrian President Bashar al-Assad in 2013 "hurt the credibility of the president's word."

Hagel, a former Nebraska senator and Vietnam War veteran, also said that the White House constantly subjected the Pentagon to debilitating micromanagement and meddling, which the men who came before him, former Defense Secretaries Robert Gates and Leon Panetta, also complained about.

Despite all that, Hagel said he still holds the president "in high regard."

"I've always had a very good, positive relationship with the president," he said.