> ‘US Americans’ makes it sound as if a distinction is being drawn between Americans inside and outside of the US or something "US Americans" is routinely used

> ‘US Americans’ makes it sound as if a distinction is being drawn between Americans inside and outside of the US or something "US Americans" is routinely used to name "people in the US", since "Americans" is ambiguous, and "US citizens" is more restrictive and explicitly excludes residents that are not citizens.