The rapid solidification of a binary mixture in the region of the interface velocities V close to the diffusion speed in the bulk of the liquid phase V D is considered within the framework of the local nonequilibrium approach. In this high-speed region the derivation of the analytical expression for the “temperature-velocity” response function representing kinetic phase diagram is given without using the concept of the equilibrium phase diagram. The modes of movement of the interface both without and with the drag effect are analyzed. It is shown that the drag effect can be accompanied by a local interface temperature maximum at .