Updated

The chairman and the Joint Chiefs of Staff unanimously supported the Obama administration's exchange of five Taliban leaders for an Army sergeant who was a prisoner of war in Afghanistan for five years.

In a series of letters, the nation's top military leaders said the United States does not leave troops behind. Gen. Martin Dempsey, the chairman of the Joint Chiefs, said the swap in May was likely the last, best chance to free Sgt. Bowe Bergdahl.

Five senior Taliban officials were released from detention at Guantanamo Bay, Cuba, in exchange for Bergdahl.

Lawmakers have raised questions about whether Bergdahl was a deserter and whether the United States gave up too much for his freedom.

Sen. Carl Levin, chairman of the Armed Services Committee, released the letters on Thursday.