The 2020 Update of the European Strategy for Particle Physics (ESPP) [1] recommended that muon beam R&D should be considered a high-priority future initiative and that a programme of experimentation be developed to determine the neutrino cross-sections required to extract the most physics from the DUNE and Hyper-K long-baseline experiments. The ENUBET [2-4] and nuSTORM [5,6] collaborations have begun to work within and alongside the CERN Physics Beyond Colliders study group [7] and the international Muon Collider collaboration [8] to carry out a joint, five-year R&D programme to deliver a detailed plan for the implementation of an infrastructure in which:• ENUBET and nuSTORM deliver the neutrino cross-section measurement programme identified in the ESPP and allow sensitive searches for physics beyond the Standard Model to be carried out; and in which • A 6D muon ionisation cooling experiment is delivered as part of the technology development programme defined by the international Muon Collider collaboration. This document summarises the status of development of the nuSTORM and 6D cooling experiments and identifies opportunities for collaboration in the development of the initiative outlined above. Elements of the proposed initiative: ENUBETThe ENUBET (Enhanced NeUtrino BEams from kaon Tagging; NP06) collaboration proposes a dedicated facility to measure ν µ and ν e cross-sections precisely using a combination of monitored, narrowband neutrino beams at the GeV energy scale and by instrumenting the meson-decay tunnel with a segmented calorimeter. The ENUBET approach is based on monitoring the production of large-angle † The nuSTORM collaboration is presented in the addendum.