sentences:  The general principles agreed to at Yalta provided the framework for the Halle discussions.With respect to the return of western Allied prisoners, the Halle meeting centered on working out the administrative details for the prompt release and return to SHAEF control of all British and American POWs, using available air or motor transport.Despite the seemingly straightforward nature of this problem, the Soviets prolonged the negotiations, citing practical and administrative obstacles and tying rapid release of American, British, and other Allied POWs to repatriation of all Soviet prisoners and displaced persons in the West, many of whom did not want to return to the Soviet Union.