grammar - Is "gonna have to" an Americanism?

First of all, I have read the answers about "gonna have to" usage, and they are quite clear:

I am gonna have to vs I have to

and

why-prefix-a-request-with-im-going-to-have-to-ask-you

The answers say that the extra words work as a politeness device. OK.

But I have heard gonna have to only from American English speakers, so my question is: Is it an Americanism?