Static field errors in a Penning‐Malmberg trap exert a drag on confined non‐neutral plasmas, causing radial expansion and loss. We suppress this transport by applying an electrostatic wall asymmetry rotating faster than the plasma. This results in inward radial transport and plasma compression. The experiments are performed on a magnesium ion plasma in a magnetic field of 4 Tesla, within situLaser Induced Fluorescence (LIF) measurement of density and temperature profiles. Confinement of ions for up to 10 days is routinely observed. © 1995American Institute of Physics