Former U.S. Defense Secretary Robert Gates is going on the offensive about the war in Afghanistan.

In a memoir to be published next week, Gates criticizes President Obama and Vice President Biden over their handling of the war.

He claims Obama did not believe in his own strategy towards the war and was convinced it would not succeed.

Gates goes on to criticize Biden saying the vice president has been "wrong on nearly every major foreign policy and national security issue."

That statement prompted a defense from White House spokesman Jay Carney.

SOUNDBITE: WHITE HOUSE SPOKESMAN JAY CARNEY, SAYING:

"As a senator and as a vice president, Joe Biden has been one of the leading statesmen of his time and he has been an excellent counselor and advisor to the president for the past five years."

Gates who served as defense secretary under both George W. Bush and President Obama is the first Pentagon chief to serve presidents of different parties.