Customs Union and Nagorno-Karabakh

Russian officials say Armenia needs to regulate customs relations with Nagorno-Karabakh before it enters the Eurasian Union. If Karabakh enters the Eurasian Union as a part of Armenia, it will indirectly lead to Nagorno-Karabakh being recognized as part of Armenia. Nagorno-Karabakh is part of Azerbaijan but has been de-facto independent since 1994. Only Armenia recognizes Nagorno-Karabakh. So far no solution has been suggested for this issue.