How to get a perfect circular UV unwrap projection? When I UV unwrap this mesh, I got those "non-circular" projections. They look weird and non-aligned...

I want them perfectly circular. What's the proper way to fix that... or isn't it possible?
As @lemon suggested me, the proper solution is selecting the right faces in the 3D Top View and UV wrap them with the Project From View option. (UProject From View).