Central Intelligence Agency director David Petraeus on Friday resigned over an extramarital affair, saying his behaviour was "unacceptable".
The top intelligence official of the United States submitted his resignation to US President Barack Obama during a meeting at the White House.
"After being married for over 37 years, I showed extremely poor judgement by engaging in an extramarital affair. Such behaviour is unacceptable, both as a husband and as the leader of an organisation such as ours," he said in a statement, according to CNN.
Obama accepted his resignation and praised Petraeus on his extraordinary service.
"I am completely confident that the CIA will continue to thrive and carry out its essential mission, and I have the utmost confidence in Acting Director Michael Morell and the men and women of the CIA who work every day to keep our nation safe," he said
"David Petraeus has provided extraordinary service to the United States for decades. By any measure, he was one of the outstanding General officers of his generation, helping our military adapt to new challenges, and leading our men and women in uniform through a remarkable period of service in Iraq and Afghanistan, where he helped our nation put those wars on a path to a responsible end," a White House statement said.
"By any measure, through his lifetime of service David Petraeus has made our country safer and stronger," it added.
Before joining the CIA, Petraeus successfully headed the US army operations in both Iraq and Afghanistan.
"Dave's decision to step down represents the loss of one of our nation's most respected public servants. From his long, illustrious army career to his leadership at the helm of CIA, Dave has redefined what it means to serve and sacrifice for one's country," James Clapper, director of National Intelligence, said.
"Since he took over as director in September of last year, he and I have worked together to tackle some of the most challenging issues faced by the intelligence community in more than a decade," he said.
"Whether he was in uniform leading our nation's troops in Iraq and Afghanistan, or at CIA headquarters leading the effort to generate intelligence used to keep our nation safe, Dave inspired people who had the privilege of working with him," Clapper said.