  In this paper we have studied the sensitivity of the future long-baseline
neutrino experiments P2SO and T2HKK to the long-range force (LRF). In the
context of these two experiments, our aim is to study: (i) the capability to
put bounds on the LRF parameters, (ii) effect of LRF in the measurement of
standard oscillation parameters and (iii) capability to constrain the mass of
the new gauge boson and the value of new coupling constant, that gives rise to
LRF due to matter density in Sun. In our study, we find that among the
different neutrino experiments, the best bound on the LRF parameters including
mass of the new gauge boson and the value of new coupling constant will come
from the P2SO experiment. Our study also shows that LRF has non-trivial effect
on the determination of the standard neutrino oscillation parameters except the
precision of $\Delta m^2_{31}$. For this parameter, the precision remains
unaltered in the presence of LRF for both these experiments.
