  We use adaptive-optics imaging and integral field spectroscopy from the Very
Large Telescope, together with images from the \emph{Hubble Space Telescope},
to study the near-infrared (NIR) evolution of the equatorial ring (ER) of
SN~1987A. We study the NIR line and continuum flux and morphology over time in
order to lay the groundwork for \emph{James Webb Space Telescope} observations
of the system. We also study the differences in the interacting ring structure
and flux between optical, NIR and other wavelengths, and between line and
continuum emission, to constrain the underlying physical processes. Mostly the
evolution is similar in the NIR and optical. The morphology of the ER has been
skewed toward the west side (with roughly 2/3 of the NIR emission originating
there) since around 2010. A steady decline in the ER flux, broadly similar to
the MIR and the optical, is ongoing since roughly this time as well. The
expansion velocity of the ER hotspots in the NIR is fully consistent with the
optical. However, continuum emission forms roughly 70 per cent of the NIR
luminosity, and is relatively stronger outside the hotspot-defined extent of
the ER than the optical emission or NIR line emission since 2012--2013,
suggesting a faster-expanding continuum component. We find that this outer NIR
emission can have a significant synchrotron contribution. Even if emission from
hot ($\sim$2000~K) dust is dominant within the ER, the mass of this dust must
be vanishingly small (a few $\times10^{-12}$~M$_\odot$) compared to the total
dust mass in the ER ($\gtrsim10^{-5}$~M$_\odot$) to account for the observed
$HKs$ flux. The NIR continuum emission, however, expands slower than the more
diffuse 180-K dust emission that dominates in the MIR, indicating a different
source, and the same hot dust component cannot account for the $J$-band
emission.
