Confinement of 4He in a porous material with nanometer - size pores suppresses both the freezing and superfluidity. In our previous investigation of superfluid density of 4He confined in a porous Gelsil glass which has pores of 2.5 nm in diameter, it was demonstrated that the superfluidity is greatly suppressed by pressurization. In order to explore the overall P - T phase diagram, we study the liquid - solid coexistence line. The freezing pressure is elevated up to about 3.4 MPa and independent of temperature below 1.3 K. Along with the previous measurement of superfluid density these features indicate that a nonsuperfluid phase exists next to the solid phase. The flat freezing curve indicates that this nonsuperfluid phase has small entropy as well as that of solid. Therefore the nonsuperfluid phase is possibly a novel ordered state, in which the global phase coherence is destroyed by strong correlation between 4He atoms and/or by random potential.