Paying the $165 fee from the UK is possibly impossible?

Right so we got the instructions on how to pay the $165 Immigrant fee- am I correct in assuming that this needs to be paid from a US checking or savings account- it seems so? I read a bit on visa journey & it looks like the site had loads of issues at first, and that someone else had this same problem. I also called the helpline & due to it being the day after a holiday in the States- the wait time was 300 minutes (lol) but the lady that was going to transfer me through did tell me that they prefer you pay it before entering- but you can pay it after. Anyone out there gone to the States & paid the $165 fee after entering? What a joke!

Thanks- this has proved more complicated than anything else!

Not sure if I ever updated info on this one: we ended up paypal-ing the money to mom Mom & she had to pay the fee as we had not set up our local accounts yet after our arrival. My hubs's "green card" arrived about 1 month after our arrival, and about 3 weeks after we paid the fee! Sooner than I thought it would! 

Glad it all worked out. We paid already online (we don't fly out till next week) but we still have our US bank account so I used that.