Meanwhile, you can communicate with them using the social networks like Facebook, Twitter or Tumblr or contact them directly by phone. Another alternative is to email them or initiate a conversation with them on skype. You can also opt travelling to that country if at all you are able once in a while to meet them.
I have moved a lot and totally understand. Write an email, Facebook, call or Skype if you can. Also find a club, class, or group in something you enjoy doing. That way you will make new friends that have a similar interest.