KABUL (Reuters) - Afghan President Hamid Karzai will travel to Qatar within days to discuss peace negotiations with the Taliban, the Afghan Foreign Ministry said on Sunday, as efforts intensify to find a negotiated solution to the twelve year war. The announcement was made only hours after another thorny issue in the U.S.-Afghan relationship -- the transfer to Afghan control of the last group of prisoners at the Bagram military complex held by U.S. forces - appeared to be resolved. The Pentagon announced on Saturday that a deal had been clinched. Karzai's Qatar trip was announced by Foreign Ministry spokesman Janan Mosazai. "President Karzai will discuss the peace process and the opening of a (Taliban) office for the purposes of conducting negotiations with Afghanistan," he said. Karzai was expected to travel to Qatar within a week, a senior Afghan official speaking on condition of anonymity told Reuters. The United States has said it would support setting up an office in the Gulf state where peace talks between the Taliban and Afghanistan could take place. "We welcome and fully support President Karzai's visit to Qatar as a sign of improved relations between the two U.S. allies," said Caitlin Hayden, a spokeswoman for the White House National Security Council. The president and other world leaders continue to call on the Afghan armed opposition to join a political process. The announcement comes several weeks after Karzai delivered a fiery speech during the first visit to Afghanistan by new U.S. Defense Secretary Chuck Hagel, in which he accused Washington of holding peace talks with the Taliban in Qatar without him. Karzai also accused the Taliban of colluding with America to keep foreign troops in the country, marking a fresh low point in the relationship between the Afghan president and his most powerful backer. Mosazai confirmed the agreement reached on the transfer of detainees held at the military detention facility at Bagram in Parwan province north of Kabul. The issue of detainees at Bagram had become another stress point in Karzai's relations with Washington. A ceremony formally transferring the last prisoners to Afghan custody collapsed two weeks ago after Karzai rejected part of the deal. American forces control an area of the prison adjacent to the Bagram military complex, which holds several dozen Taliban fighters considered by the United States to pose the most severe threat. Washington is concerned the Afghans may release some of these men when control of the prison is handed over. That concern was reinforced during Karzai's outburst this month, in which he said the United States had been dragging its heels on prisoner transfers and said he would release those detainees that were "innocent." Under the terms of agreement, all Afghans detained by forces of the U.S.-led coalition would now have to be handed over to Afghan control within 96 hours of capture, Mosazai said. Any decision to release them after that would be made only by the Afghan government. Writing by Dylan Welch; additional reporting by Mark Felsenthal in Washington; Editing by Ron Popeski and Xavier Briand