Trump has also rejected growing calls for sweeping police reform proposals in the aftermath of Floyd's killing.

The military has been given sweeping police powers it last used during a devastating civil war that ended in 2009.

Republicans immediately tried to portray Harris as a "radical" who embraces far-left priorities such as sweeping police reform and a ban on fracking.

The killing sparked enormous protests in towns and cities across the US and spurred urgent calls for sweeping police reform by both lawmakers and activists.