I will have to urgently have a hysterectomy done, however, I don't have health insurance and I am not a US citizen, meaning, I will have to pay out of pocket. My question is, there any charity that would be in the position to assist me pay part of the fee?

Do you belong to a local church or civic organization? They may have funds set aside to assist with medical expenses.

I was an active member of a local church but I permanently moved out of US a couple of years ago just returned a couple of weeks ago I am not sure if it would appropriate to visit and ask

It can't hurt to ask; seeing that your reason for leaving was because you moved away, they may be willing to at least offer some help.

Talk to the hospital's billing department BEFORE your hospitalization. Most hospitals have charities that contribute money to the hospital for situations just like this.