AbstractJoint work on the design of the International Thermonuclear Experimental Reactor (ITER) has provided an opportunity for engineers and physicists from Japan, the EC, USA and Soviet Union to compare concepts and identify critical data needs which must be evolved over the next few years to support the design of the next-step machine for magnetic-confinement fusion. In the fuel cycle area, well-developed national programs exist, and the challenging task of the Fuel Cycle Design Unit in ITER is to promote a harmonisation of these tasks to minimise duplication and ensure gaps which would affect the development of satisfactory design concepts do not occur. The principle mechanisms for this involves: •- identification of a subset of R&D task where results are especially needed for design,•- establishment of task and subtask definitions and program milestones to facilitate task monitoring,•- reporting and information exchange as results become available.Results of this exercise to-date are described in this note.