US Smartthings hub with UK Philips Hue hub

I bought a Smartthings hub while I was on honeymoon in America because of how much cheaper it was than in the UK. I have set it up, where I had to say my location was the US so that the welcome code would work.

I am trying to connect it to my Philips Hue hub but when I choose add a thing it just sits there looking for devices and doesn’t find anything.

Am I doing something wrong or is there a compatibility issue because the ST hub is from the US and the Philips hub is from the UK?

Thanks!