(CNN) -- David Petraeus stepped down as the director of the CIA on Friday, citing an affair.
"After being married for over 37 years, I showed extremely poor judgment by engaging in an extramarital affair. Such behavior is unacceptable, both as a husband and as the leader of an organization such as ours," he said in a statement.
President Barack Obama accepted his resignation.
A retired Army general who served as the top U.S. commander in Iraq and Afghanistan, Petraeus was sworn in as the head of the CIA in September 2011.
Director of National Intelligence James Clapper issued a statement Friday confirming that Petraeus had turned in his resignation, saying his "decision to step down represents the loss of one of our nation's most respected public servants."