This thread is resolved. Here is a description of the problem and solution.
Problem: The client wishes to add American and Australian English to their site, which are not available by default in WPML's language options. Solution: We recommend manually adding these language variations to WPML. To do this, please follow the step-by-step guide on how to add a custom language:
If this solution does not apply to your situation because it might be outdated or not relevant to your case, we suggest opening a new support ticket. We also highly recommend checking related known issues, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.
If you need further assistance, please do not hesitate to contact us in the WPML support forum.
This is the technical support forum for WPML - the multilingual WordPress plugin.
Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.
I understand what you're looking for. The languages you've mentioned are variations of English language and they are not listed in WPML's default language selection. If you want to translate and display content into these specific variations, you will need to manually add the languages into WPML.
I hope it will help in achieving what you're looking for. Please feel free to let me know if there is anything else you need help with. I will be happy to assist.