By Jim Sciutto
WASHINGTON (CNN) -- The U.S. military has obtained new video apparently made by those holding the lone American prisoner of war, Army Sgt. Bowe Bergdahl.
A U.S. military official told CNN the clip shows the Wood Valley, Idaho, native in diminished health from the effects of close to five years in captivity.
He was seized in Afghanistan in June 2009 and is believed held by the Taliban-aligned Haqqani network in Pakistan, the official said.
The so-called proof-of-life video, the first of him in nearly three years, has a reference to December 14, 2013.
CNN has not seen the video.
The network has contacted Bergdahl's family, which last year received a letter from him via the Red Cross.
U.S. efforts to free Bergdahl, including negotiating for his release, have so far failed.
"Sgt. Bowe Bergdahl has been gone far too long, and we continue to call for and work toward his safe and immediate release," a Pentagon spokesman said.
"We cannot discuss all the details of our efforts, but there should be no doubt that on a daily basis -- using our military, intelligence and diplomatic tools -- we work to see Sgt. Bergdahl returned home safely," the spokesman said.
Bergdahl was 23 when he was captured after finishing a guard shift at a combat outpost in southeastern Paktika province.
The U.S. government acknowledged in May 2012 that it was engaged in talks with the Taliban to free Bergdahl.
The discussions moved in fits and starts because of U.S. concerns that any Taliban prisoners swapped for Bergdahl might be repatriated and allowed to rejoin the fight.
Later that year, however, the White House announced it was willing to send five Taliban prisoners to Qatar in exchange for Bergdahl.
™ & © 2014 Cable News Network, Inc., a Time Warner Company. All rights reserved.