FILE - In this July 30, 2012, file photo, transfer cases containing the remains of Army Spc. Benjamin C. Pleitez, left case, Army Sgt. 1st Class Bobby L. Estle, right case and Army Pfc. Jose Oscar Belmontes, case not shown, sit on a loader during a prayer at Dover Air Force Base, Del. According to the Department of Defense, Pleitez, 25, of Turlock, Calif., died July 27, 2012 in Mazar-e-Sharif, Afghanistan and Estle, 38, of Lebanon, Ohio, and Belmontes, 28, of La Verne, Calif., both died July 28, 2012 in Wardak province, Afghanistan, of wounds sustained from enemy small arms fire. U.S. troop deaths in Afghanistan have plunged to the lowest level in four years, reflecting a pullback from direct combat into the less deadly role of advising and assisting Afghan forces as they do more of the fighting. Attacks by the Taliban insurgents also have been declining, although the war is far from finished. (AP Photo/Steve Ruark, File)

FILE - In this Dec. 12, 2012, file photo, U.S. Defense Secretary Leon Panetta, right, shakes hands with Marine Gen. John R. Allen, left, commander of International Security Assistance Force, as U.S. Ambassador to Afghanistan James B. Cunningham, center, watches, upon Panetta's arrival at Kabul International Airport in Kabul, Afghanistan. U.S. troop deaths in Afghanistan have plunged to the lowest level in four years, reflecting a pullback from direct combat into the less deadly role of advising and assisting Afghan forces as they do more of the fighting. Attacks by the Taliban insurgents also have been declining, although the war is far from finished. (AP Photo/Susan Walsh, Pool)

FILE - In this July 7, 2012, file photo, Secretary of State Hillary Rodham Clinton, right, greets troops before departing Kabul International Airport. U.S. troop deaths in Afghanistan have plunged to the lowest level in four years, reflecting a pullback from direct combat into the less deadly role of advising and assisting Afghan forces as they do more of the fighting. Attacks by the Taliban insurgents also have been declining, although the war is far from finished. (AP Photo/Brendan Smialowski, File, Pool)

In this Sunday, Jan. 27, 2013 photo, U.S. Marine Gen. John Allen, the top commander of U.S.- and NATO-led International Security Assistance Force (ISAF) troops in Afghanistan, speaks during an interview with The Associated Press in Kabul, Afghanistan. Allen expressed confidence that Afghan security forces will be able tackle the insurgency when they take the lead in the 11-year-old war against the Taliban this spring, and will be able to hold their own against the Taliban on the battle field without the presence of foreign troops fighting on the front line. (AP Photo/Musadeq Sadeq)

In this Sunday, Jan. 27, 2013 photo, U.S. Marine Gen. John Allen, the top commander of U.S.- and NATO-led International Security Assistance Force (ISAF) troops in Afghanistan, speaks during an interview with The Associated Press in Kabul, Afghanistan. Allen expressed confidence that Afghan security forces will be able tackle the insurgency when they take the lead in the 11-year-old war against the Taliban this spring, and will be able to hold their own against the Taliban on the battle field without the presence of foreign troops fighting on the front line. (AP Photo/Musadeq Sadeq)