A technical snag was observed in launch vehicle system at T-56 minute.
Minutes before making this announcement, the officials put on hold the countdown.
A revised launch date for the mission would be announced later, said the national space agency in a Twitter post.
The mission was originally scheduled for launch at 2:51 am on Monday from Satish Dhawan Space Centre, Sriharikota in Andhra Pradesh. While all preparations were done, with the filling of liquid hydrogen and oxygen in the launch vehicle completed, the launch was put on hold around 2:30 am.
Chandrayaan-2 is the most complex and prestigious that Isro has ever undertaken, reported news agency PTI.
The mission will make India the fourth country after the US, USSR, and China to land on the moon.