Washington (CNN) The Trump administration doesn't need Congress to pass a law or make a sweeping regulation to overhaul the US immigration system -- it's already doing it through a series of small moves that add up to dramatic change.

While the administration continues to pressure Congress to grant it broad new authorities, just the past week illustrates how substantial a change is already underway, with each individual move adding up to an effort that could have lasting effects on how the US welcomes and evaluates immigrants.

Since last Thursday, here are some of the moves the administration has made:

And that was all just one week.