Donald Rumsfeld: John McCain 'Not A Good Fit' (VIDEO)

During an appearance on ABC's "Good Morning America" on Tuesday, former Defense Secretary Donald Rumsfeld addressed friction that appears to exist between himself and Arizona Senator John McCain.

In his new memoir Known and Unknown, Rumsfeld describes the Republican lawmaker as "a man with a hair-trigger temper and a propensity to fashion and shift his positions to appeal to the media."

After the harsh characterization was leaked prior to the book's release, McCain hit back at Rumsfeld during an appearance on GMA.

"Thank God he was relieved of his duties," the Arizona senator said. He also admitted that the pair had a contentious working relationship that often put them at odds over policy related to the country's military presence in Iraq.

Rumsfeld is now sounding off on the pair's relationship in the wake of the remarks.

WATCH: