Hello,
For a couple of versions, dwg imports handle autocad regions. Importing and Exporting CAD Files | SketchUp Help, confirmed by the import dialog that reports imported regions.
But I find the result not very exploitable.
See for yourself :
Autocad Region.skp (285.6 KB)
Autocad Region.dwg (77.6 KB)
It imports a smoothed face and deleting the face would also delete its outline, unless we unsmooth it and smooth it again.
note : I have autocad 2014, saving dwg as 2010 version