UK guy here, who's had plenty of fun in the US.
No matter where you go, you will find women with loose morals, and I am sure I can point you in the direction of a few places in the UK where this would be so (Nottingham for starters, Manchester for gay / bi from what me mate John tells me), and I would say the US would be no different.
From my perspective, I find US women to be more relaxed and open, but this has only been my own experience, and this was mostly down to the people I chose to mix with as a group.
Poor choice of words from the OP, which I believe was trying to ask.... Which cultures generally have a more relaxed attitude with regards to sex.
Generally in Japan for EG, I see the women having a more caring approach to relationships, as that is how the culture there is.