They did not see the new moon of Dhu’l-Hijjah – what should they do?

I am a Sunni Muslim living in Japan, writing to ask you about the sighting of the new moon of Dhu’l-Hijjah, because the Muslims are disputing about the day of Eid.
 My question here is should we celebrate Eid with Saudi Arabia or should we follow the closest (Muslim) country to us?.