  Close binary systems consisting of two neutron stars (BNS) emit gravitational
waves, that allow them to merge on timescales shorter than Hubble time. It is
widely believed, that NS-NS mergers in such systems power short gamma-ray
bursts (GRB). Several mechanisms which could lead to electromagnetic energy
release prior to a merger have been proposed. We estimate the ability to
observe the possible pre-burst emission with telescopes of
Spectrum-Roentgen-Gamma. We also investigate first such event, GRB210919A,
which fell into the field of view of the SRG telescopes less than two days
before the burst.
