U.S. President Barack Obama on Wednesday announced he has accepted the resignation of General Stanley McChrystal, commander of U.S. forces in Afghanistan, and is to nominate General David Petraeus, commander of U.S. Central Command, to take over the war in Afghanistan.

Flanked by Vice President Joe Biden, Defense Secretary Robert Gates, Chairman of the Joint Chiefs of Staff Mike Mullen and Petraeus, Obama announced the decision after an hour-long meeting of his advisers on Afghanistan war. He said the behavior of McChrystal, who made disparaging remarks about senior administration officials, was unbecoming.

"The conduct represented in the recently published article does not meet the standard that should be set by a commanding general," Obama said, noting it undermined civilian control of the military and the ability of the team handling the Afghanistan war to work together, emphasizing he "won't tolerate division."

"As difficult as it is to lose General McChrystal, I believe that it is the right decision for our national security," Obama said, telling troops they must obey conduct code, which applies equally to all military personnel.