  We report the accurate sub-arcsec X-ray position of the new Anomalous X-ray
Pulsar (AXP) XTE J1810-197, derived with a Chndra-HRC Target of Opportunity
observation carried out in November 2003. We also report the discovery of a
likely IR counterpart based on a VLT (IR band) Target of Opportunity
observation carried out in October 2003. Our proposed counterpart is the only
IR source (Ks=20.8) in the X-ray error circle. Its IR colors as well as the
X-ray/IR flux ratio, are consistent with those of the counterparts of all other
AXPs (at variance with field star colors). Deep Gunn-i band images obtained at
the 3.6m ESO telescope detected no sources down to a limiting magnitude of
24.3. Moreover, we find that the pulsed fraction and count rates of XTE
J1810-197 remained nearly unchanged since the previous Chandra and XMM-Newton
observations (2003 August 27th and September 8th, respectively). We briefly
discuss the implications of these results. In particular, we note that the
transient (or at least highly variable) nature of this AXP might imply a
relatively large number of hidden members of this class.
