The parents of Sgt. Bowe Bergdahl, a United States soldier taken prisoner by Taliban affiliates, have revealed previous secret attempts by the U.S. to trade him for Taliban prisoners.

Bowe Bergdahl, a 26-year-old from Idaho, has been in Taliban captivity for the last three years. It is believed that the sergeant is being held somewhere in Pakistan by the Haqqani network, a group of insurgents with Taliban association.  

The reported proposed prisoner swap would see the Obama administration allowing the transfer of five Taliban prisoners held at Guantanamo Bay, Cuba.

The Associated Press, which has reported on the soldier's case since his capture, said it agreed last year to not to report on the proposed prisoner swap and the ongoing negotiations. This was because the Pentagon believed discussing the matter publicly would endanger the soldier's life.

However, Bob Bergdahl and his wife, Jani Bergdahl, spoke to the Idaho Mountain Express and Guide on Wednesday, saying that they believe Bowe is alive and that aggressive negotiations or a prisoner exchange could bring his return.

The parents have grown frustrated with the U.S. government's inability to negotiate the soldier's release, the Idaho paper reported.

There is a dynamic here that has changed, Bob Bergdahl told the paper. Everybody is frustrated with how slowly the process has evolved.

According to the AP, the proposed deal between the U.S. and the Taliban has stalled for months. And, should it get off the ground, the proposal faces tough opposition in Congress. The Taliban walked away from the proposed deal talks in March, and said the U.S. broke several promises.

Two U.S. officials told the AP that the Obama administration is trying several strategies to restart talks. These include proposing looser terms for the detention, or monitoring, of at least one of the prisoners when the release takes place.

I'm pushing it hard, the father said of the prisoner swap idea. We started out by trying to encourage the Taliban to take care of our son. ... Now, we're worried that the government isn't concerned enough to put him on the (negotiating) table.

The father told the Idaho paper that a swap deal with the Taliban would be a win-win for the U.S.

Bowe was serving with the U.S. Army in Afghanistan.