SEO for multiple markets with the same language

[Ogenstad]

If for example I have two markets and they both have English, how do I differentiate page titles, etc.? Since search engines don't like the same page occurring multiple times.

https://mysite.com/en-gb/my-product

https://mysite.com/en-us/my-product

Both of these URL's will have the same content, title and description. What is best practice here?