Hailey , Idaho ( CNN ) -- The father of the only American POW in Afghanistan sent a message to his son 's Taliban captors on Saturday : `` After 12 years , let there be peace . Can we push this forward and make it happen ? '' And he sent a message to his son : `` I will not leave you on the battlefield . You are not forgotten . '' Updates about Sgt . Bowe Bergdahl 's case have been sparse since he was captured nearly four years ago after finishing a guard shift at a combat outpost . Family members have remained reticent for fear of jeopardizing his safety . But the 27-year-old soldier 's parents spoke out at a rally in home state of Idaho on Saturday , just days after U.S. authorities said discussion of a possible prisoner exchange with the Taliban could be on the table during upcoming talks . `` We are feeling optimistic this week , '' mother Jani Bergdahl said . `` So many of you have come from far away , and we appreciate the sacrifices you made to make this possible . '' More than 1,000 people were in the crowd , including hundreds of war veterans who rode motorcycles into this town . Throughout the event , they chanted , `` Bring Bowe Home . '' Local politicians , state senators and police officials also spoke at the event . `` We hope he will see this and know of you , '' his mother told the crowd . Then , she sent a message to her son , `` We love you and are eagerly awaiting your return home . '' In a statement released earlier this week through a family spokesman , the soldier 's parents said they were encouraged by word that upcoming negotiations might lead to their son 's freedom . `` That is encouraging news , especially after not much encouraging news over the past four years , '' Army Col. Tim Marsano said , adding that the Bergdahls have been talking with military and government agencies . `` They know their son has not been forgotten . My brothers and sisters in uniform know we wo n't rest until Bowe Bergdahl is safely back with his family . '' At Saturday 's rally , father Bob Bergdahl sported a long beard , which he has grown out since his son 's capture as a sign of solidarity . And he spoke briefly in Pashto , a language that he 's studied during his son 's captivity . He offered a message that he said was meant for the Taliban . `` May the peace of God and blessings of God be upon you , '' he said . `` After 12 years , let there be peace . Can we push this forward and make this happen ? '' Speaking in English , he offered a message in English that he said was meant for his son . `` Bowe , my son , if you can hear me . ... you are part of the peace process , you are part of ending the Afghan war . Have faith . Do good works . Tell the truth , and have the patience that can only come from God . We are being tested , '' Bob Bergdahl said . On Thursday , State Department spokeswoman Jennifer Psaki said the U.S. expects prisoner exchange to be a topic of talks with the Taliban , which are slated to take place `` in the coming days , '' in Doha , Qatar . No decisions have been made about transferring any Taliban detainees held at Guantanamo Bay . Any such decision would have to be made with congressional approval and in accordance with U.S. law , she said . It wo n't be the first time U.S. negotiators raise the issue of Bergdahl 's release with the Taliban . The two sides held meetings in 2011 and 2012 that included the topic of Bergdahl 's release , with sporadic discussions since then . While the United States has been pushing for the return of Bergdahl -- captured in June 2009 in Afghanistan -- the Taliban has been pushing for the release of five of its own men from U.S. custody in Guantanamo Bay . Psaki said the United States expects the Taliban will raise that issue again when the two sides meet . In the meantime , Bergdahl 's father said Saturday that he 'll never stop pushing for his son 's freedom . `` A father does not leave his son on the battlefield . I live in Afghanistan , my phone on Afghan time , '' he said . `` I will not leave you on the battlefield . You are not forgotten . You will not be forgotten . We pray soon you will come home . '' CNN 's Eliott C. McLaughlin and Melissa Gray contributed to this report .
Dad 's words to POW son : `` I will not leave you on the battlefield . You are not forgotten '' Sgt . Bowe Bergdahl 's parents speak out at a rally in Idaho . Bergdahl is the only American prisoner of war in Afghanistan . His father send the Taliban a message of peace .