safer and more secure than it was four years ago, and we have reached a turning point after more than a decade of war," Panetta said in his remarks at the White House.
President Barack Obama has nominated Chuck Hagel, the former Republican Senator, as his next Defence Secretary to replace Panetta and John Brennan as his next CIA Director.
"And on that, as we've reached that turning point, we've developed a new defence strategy for the 21st century. We have, with John's leadership, decimated al-Qaeda's leadership and weakened their effort to attack this country," Panetta said in his statement.
"We have brought wars in Iraq and we will bring the war in Afghanistan to an honorable conclusion. We've opened up opportunities for all Americans to serve in our military. And we continue to strongly support our forces, their families, and our wounded warriors. These are some of the achievements that I am proud of," he said.
Panetta said after being in public life for five decades he would return to private life and to his home in California.
"As for me, after close to 50 years of serving the American people - began in 1964, when I served as a first lieutenant in the United States Army, and then in both the legislative and executive branch positions in Washington - the time has come for me to return to my wife, Sylvia, our three sons, their families, our six grandchildren, and my walnut farm dealing with a different set of nuts," he said amidst laughter.
"I will leave Washington with a very deep sense of pride in what we have accomplished during these last four years being on the president's national security team," he said.
Commending Obama on his decision to nominate Hagel as the next Secretary of Defence, he said he has known him for a long period of time.
"I had the opportunity to work with him closely, particularly in his capacity as chairman of the president's intelligence advisory board. I greatly appreciate the work he has done to strengthen our intelligence enterprise. It has been extremely important to our ability to improve our intelligence capabilities," Panetta said of Hegal.
"And as secretary of defense, I also benefited from his work when he served on our Defense Policy Board," he said.
"Hagel is a patriot. He's a decorated combat veteran. And he is a dedicated public servant. I believe his experience, his judgment, his deep understanding of the security issues facing this country make him the right choice to be secretary of defense," Panetta said.