Can I buy US Treasuries at my bank?

Excuse me, I was wondering if I could possibly purchase United States Treasuries through my local bank? I've heard they're a relatively SAFE investment option and I'm looking to diversify my portfolio. Do banks typically offer this service, or would I need to go through a broker or another financial institution? Additionally, if they do offer this service, could you please elaborate on the process and any potential fees or requirements I should be aware of? Thank you in advance for your assistance.