[en] A coupled-channels approach is used for incorporating NΔ configurations into the mechanism of the meson production reaction p+p→d+π⁺. The differential cross sections and the polarization asymmetry are calculated for lab energies ranging from threshold to 750 MeV including the partial waves up to f-wave pions and ³F state nucleons. It is found that the pp state ³F₃ is important in obtaining a reasonable agreement with the existing experimental data. A remarkable insensitivity of the differential cross section to the D-state probability of the deuteron is found whereas the polarization is somewhat dependent on this. (Auth.)