  We study solitons in the two-dimensional defocusing nonlinear Schroedinger
equation with the spatio-temporal modulation of the external potential. The
spatial modulation is due to a square lattice; the resulting macroscopic
diffraction is rotationally symmetric in the long-wavelength limit but becomes
anisotropic for shorter wavelengths. Anisotropic solitons -- solitons with the
square (x,y)-geometry -- are obtained both in the original nonlinear
Schroedinger model and in its averaged amplitude equation.
