WATCH: U.S. Soldier Says Bergdahl's 'Desertion Was Premeditated'

Specialist who fought alongside the recently released prisoner in Afghanistan calls Berghdahl's desertion 'the ultimate betrayal.'

A member of the platoon of Bowe Bergdahl, a U.S. soldier recently released from Taliban custody in a prisoner exchange, told members of the U.S. Congress the 28-year-old soldier deserted, saying Bergdahl's actions were "premeditated" and that he "had a plan and executed it."

Retired Army Spc. Cody Full served with Sgt. Bergdahl in Blackfoot Company, Second Platoon. "The facts tell me that Bergdahl's desertion was premeditated. He had a plan and was trying to justify it in his head. How long he had planned this, I do not know. But, it is clear to me that he had a plan and executed it. Countless looked for him when he went missing, putting their own lives on the line for his. Combat is difficult. The only thing you can count on in combat is the commitment of your fellow American. Knowing that someone you needed to trust deserted you in war, as did Bowe, [who] did so on his own free will, is the ultimate betrayal," Full told a Congressional hearing.

The Obama administration's decision to exchange Bergdahl for five prisoners from the Guantanamo Bay military prison caused a political firestorm, with Republican lawmakers and many of Obama's fellow Democrats angry the White House did not inform Congress.

The five detainees are being held in Qatar for a year. Republican lawmakers who oppose closing the Guantanamo prison have been fiercely questioning whether the Gulf Arab state will keep the prisoners secure.