FILE - This July 22, 2012, file photo shows U.S. Gen. John Allen, top commander of the NATO-led International Security Assistance Forces (ISAF) and U.S. forces in Afghanistan, during an interview with The Associated Press in Kabul, Afghanistan.
Marine Gen. John Allen, the former top American commander in Afghanistan and President Barack Obama's nominee to lead U.S. and NATO forces in Europe, announced Tuesday that he will retire from the U.S. military after 38 years of service, citing personal reasons.
"While I won't go into the details, my primary concern is for the health of my wife, who has sacrificed so much for so long," he said in a statement. "For more than 35 years, my beloved Kathy has devotedly stood beside me and enabled me to serve my country."
He added that it was "profoundly sobering" to consider the amount of time he has spent away from his two daughters over the course of his career.
His decision comes just weeks after his name was cleared in an investigation into his conduct with Jill Kelley, a Florida socialite who was linked to scandal that ended David Petraeus' career at the CIA.
President Barack Obama said he accepted the request, calling Allen one of the nation's finest military leaders and a true patriot.
Last week, NBC News cited three U.S. officials in reporting that Allen had been likely to withdraw his name for the nomination to be the next NATO Supreme Allied Commander in Europe.
Allen did not want to put his family through a nomination process that would bring up the Kelley emails, several military officials also told NBC News.
In an interview with the Washington Post Monday evening, Allen said that the probe, which examined his relationship with Kelley and had investigators combing through batches of his emails for signs of inappropriate behavior, had taken a toll on his wife, who suffers from chronic health problems including an autoimmune disorder.
"For a long time, I told her, 'When you can't bear this anymore, just tell me and I'll drop my [resignation] letter right away," Allen told the Post. "Now I need to be the one who takes this out of her hands."
A four-star general, Allen was a key player in the development of Afghan troops and transitioning of power from international forces to local security forces as the U.S. began its drawdown.
Outgoing Defense Secretary Leon Panetta, who worked closely with Allen during his tenure, said that "his leadership over the last 19 months will long be remembered as pivotal to this campaign" in Afghanistan. "The strategy he developed and implemented has put us on the right path towards completing this mission, with Afghan forces now on track to step into the lead for security nationwide this spring and to assume full security responsibility by the end of next year."
Here is President Obama's statement on Tuesday:
Today, I met with General John Allen and accepted his request to retire from the military so that he can address health issues within his family. I told General Allen that he has my deep, personal appreciation for his extraordinary service over the last 19 months in Afghanistan, as well as his decades of service in the United States Marine Corps. General Allen presided over the significant growth in the size and capability of Afghan National Security Forces, the further degradation of al Qaeda and their extremist allies, and the ongoing transition to Afghan security responsibility across the country. He worked tirelessly to strengthen our coalition through his leadership of the International Security Assistance Force (ISAF), and to improve our relations with the Afghan government. Above all, he cares deeply for the men and women in uniform who serve our nation - as well as their families - and I am grateful for the sacrifices made by his family in supporting him during his service. John Allen is one of America's finest military leaders, a true patriot, and a man I have come to respect greatly. I wish him and his family the very best as they begin this new chapter, and we will carry forward the extraordinary work that General Allen led in Afghanistan.