Both words are used in all varieties of English, whether British or American.
They are not archaisms. They are both used in modern English.
I don't think there is much more that I can explain. You can use either word.
The hotel is located just one block north of the post office. (Sounds like ordinary, everyday, conversational English)
The hotel is situated just one block north of the post office. (Sounds more formal. Maybe this is written in a travel brochure. Or perhaps it's being said by a man wearing a tuxedo!)
CJ