I am creating a new multilingual website where we have a single primary domain (.com) and the language is handled via different URL routings e.g:

www.foobar.com/US/About
www.foobar.com/UK/About
www.foobar.com/DE/About

I have the facility for the user to change the region from those available at any time during their stay on the website. The selection is stored in a cookie and is automatically applied on any subsequent visit.

Should a user navigate to a URL without any region specified e.g.

www.foobar.com/About

The system defaults to US and redirects automatically to

www.foobar.com/US/About

This is working perfectly and the client is happy with this.

The client has now asked that on the first visit to the site the user is presented with a "pop-up" that forces them to choose a region - to ensure that they are looking at relevant content.

Whilst I appreciate his concern I am looking for a less intrusive mechanism of clearly highlighting that a region selection is available on first visit - this must also work well on mobile devices.

The currently selected region is displayed using a clearly visible "flag" icon at the right-hand side of the navigation bar (24px x 24px) - but I am thinking I could just highlight this somehow on first visit to make it clearly noticeable, but I had also considered a sliding div (from top or side of page) or a bootstrap dialog.

Does anyone have any thoughts on how to handle this cleanly without irritating new visitors?