(CNN) -- In an effort to revive peace talks with the Taliban, the Obama administration has sweetened a proposed prisoner swap under which it would transfer five Taliban prisoners to Qatar in exchange for a U.S. soldier held by the Taliban, senior U.S. officials said.

The new proposal involves sending all five Taliban prisoners to Qatar first, before the Taliban releases Sgt. Bowe Bergdahl, the sources said. The original offer proposed transferring the Taliban prisoners into two groups, with Bergdahl being released in between.

The new offer was first reported by Reuters.

The officials stress that the exchange, should it take place, would be implemented in accordance with U.S. law, which requires consultations with Congress before any detainees are transferred from Guantanamo.

At a State Department briefing Wednesday, Patrick Ventrell, an acting deputy spokesman, said the release of the detainees is not a sure thing.

"At this point, the United States has not decided to transfer the Taliban detainees from Guantanamo Bay," he said.

He added that the U.S. does not discuss its internal deliberations on the issue.

Washington has hoped the prisoner exchange would be seen as a good-faith gesture in initial talks between U.S. and the Taliban, which would pave the way for formal reconciliation talks between the Taliban and the Afghan government of President Hamid Karzai.

For months, U.S. officials have acknowledged ongoing negotiations with the Taliban that include the American proposal for the release of Bergdahl, who was captured in Afghanistan in June 2009. The officials told CNN there have been a series of "confidence-building measures" discussed for his release in the context of reconciliation talks, which have been stalled.

Bergdahl's family has also told news organizations the fate of their son was part of the negotiations. In May, the family told The New York Times they were speaking out because of frustration over a lack of progress in the talks.

U.S. Special Representative for Afghanistan and Pakistan Marc Grossman raised the revised proposal in June with officials in Qatar, which has played a key role in talks over the last two years between the U.S. and Taliban. Grossman had met with Taliban representatives earlier this year and in a series of talks in 2011. The talks have now largely been suspended. The Taliban suspended its diplomatic office in Qatar in March, complaining of the United States' "alternating and ever-changing position."

U.S. officials cite a series of indicators that the Taliban is under pressure from NATO and Afghan forces and could be ready to talk about a deal to end the Afghan war.

James Cunningham, the new U.S. ambassador to Afghanistan, told a Senate panel in July at his confirmation hearing that Taliban leaders are "signaling they are open to negotiations," although he said the Taliban must end its alliances with terrorist groups like al Qaeda before the U.S. would endorse any peace deal.

Other officials have pointed to statements by Taliban representatives distancing themselves from the group's relationship with al Qaeda and saying that they would be willing to accept ideas supported in Afghan society, like sending girls to school. Recently, Karzai invited Taliban leader Mullah Omar to take part in the Afghan political process, and last month, a Taliban representative attended an international conference on Afghan reconciliation in Japan.

"These are choices the Afghans and Taliban make, but we have seen some movement in the past few months," one senior official said. "Increasingly, there is an Afghan population that is turning away from the Taliban and a drumbeat of Taliban saying we don't think we can win this and we are getting left behind, so maybe we should talk."

Given the improved climate, officials suggest the revived prisoner deal could be an impetus to jumpstart talks.

"Whether this is going to work or whether it is going to lead to anything, who knows," one senior official said.

The idea of releasing the Guantanamo prisoners to encourage reconciliation talks has been controversial and met with opposition from some key members of Congress, who warned that the release would send the wrong message to the Taliban.

There have been concerns on the U.S. side that not enough assurances had been given in Qatar that the released detainees would not be able to return to Afghanistan and rejoin the fight.

Officials have long said Bergdahl is believed to be in Pakistan, held by the Haqqani network, which is thought to be moving him around often, making it difficult to track him. The United States, he said, has been pressing the Pakistanis as well to get him released.