We develop an iterative, numerically exact approach for the treatment
of nonequilibrium quantum transport and dissipation problems that
avoids the real-time sign problem associated with standard Monte-Carlo techniques. The method requires a well-defined decorrelation time of
the non-local influence functional for proper convergence to the exact limit. Since this finite degree of non-locality may arise either from
temperature or a voltage drop, the approach is ideally suited for the description of the real-time dynamics of single-molecule
devices and quantum dots driven to a steady-state via interaction with two or more electron leads. We numerically investigate two
non-trivial models: The evolution of the nonequilibrium population of a two-level system coupled to two electronic reservoirs, and quantum
transport in the nonequilibrium Anderson model.