What action is taken to counteract the gradual altitude loss experienced by the ISS?

Answer

Mission control commands attached Russian Progress cargo vehicles or other docked craft to perform a reboost burn.

To maintain orbit, mission control periodically commands attached craft, such as the Russian Progress vehicles, to perform a reboost burn to push the station back into a higher orbit.

What action is taken to counteract the gradual altitude loss experienced by the ISS?
SpaceorbitISSKármán line