I called back and it instantly went to a recording asking if I wanted my # placed on a do not call list. Definitely don't enter your number, I'm sure that will be rewarded with even more calls.
5/12 CID 'United States' - several rings, disconnect, no mag - typicsl scam call pattern - from all above posts seems to be a new 'int rate reduction, etc. scam - recommend blocking, if possible