New reports have emerged indicating that the Obama administration was aware of Army Sgt. Bowe Bergdahl's decision to walk away from his base in Afghanistan on June 30, 2009.

Since at least December 2009, President Obama's principal military adviser, then-Chairman of the Joint Chiefs of Staff Admiral Mike Mullen, knew that Bergdahl had deserted, three of Bergdahl's platoon mates told Fox News.

Former Sgt. Matt Vierkant told Fox News, "I asked him (Mullen) if he knew about Bergdahl and that he deserted and he (Mullen) told me that he knew of the circumstances surrounding his walking off, and that they were developing leads and following leads, trying to do everything they could to get him back."

Despite knowing of Bergdahl's willful desertion and intention to renounce his citizenship, the administration still sacrificed the lives of six military members while looking for him, exchanged five of the most dangerous Taliban commanders in U.S. custody for his release, spent $1 million in taxpayer dollars on his retrieval, and then praised him for serving with "honor and distinction."

The three soldiers who served with Bergdahl - Matt Vierkant, Evan Buetow and Cody Full - had been working security duty for Mullen while he was touring through Afghanistan in December 2009. Following a pep talk delivered by Mullen, the chairman decided to host an impromptu Q&A session, which is when the soldiers inquired about Bergdahl's status.

"So Matt asked him, you know Bergdahl deserted, what's going on with that? And Admiral Mullen said, 'Yes, we know all the circumstances surrounding Bergdahl walking away from the OP (outpost), and we're still working on getting him back, figuring out where he is and kind of figuring out that whole situation,'" reported Fox News.

Vierkant said there was absolutely no ambiguity as to whether Mullen knew that Bergdahl had deserted.

"Without a doubt, he (Mullen) knew he (Bergdahl) deserted or, you know, was suspected of desertion. There was no doubt in my mind thet he fully understood what Bergdahl did," he said.

Naturally, the exchange with Mullen left the soldiers wondering why the administration would go through so much trouble to rescue someone who didn't seem like they wanted to be rescued.

"I want to ask him (Mullen) did they brief the White House? Who knew about it and why would you still do this trade knowing all the information that you knew?" Vierkant told Fox News. "We don't leave anyone behind. The thing is, we never left him (Bergdahl) behind. He left us behind. He chose to walk off and do whatever and get captured, that was his fault. Those were his choices."

Bergdahl faces up to life in prison if he is convicted of charges brought against him by the U.S. military: desertion and misbehavior before the enemy. He is expected to appear before a military court martial in the summer.