  We design a plasmonic fiber waveguide (PFW) composed of coaxial cylindrical
metal-dielectric multilayers in nanoscale, and constitute the corresponding
dynamical equations describing the modes of propagation in the PFW with the
Kerr nonlinearity in the dielectric layers. The physics is connected to the
discrete matrix nonlinear Schr\"{o}dinger equations, from which the highly
confined ring-like solitons in scale of subwavelength are found both for the
visible light and the near-infrared light in the self-defocusing condition.
Moreover, the confinement could be further improved when increasing the
intensity of the input light due to the cylindrical symmetry of the PFW, which
means both the width and the radius of the ring are reduced.
