The launch of Japan's first dedicated military communications satellite will be delayed by two years after a mishap with a blue tarpaulin damaged sensitive antennas during transportation to Europe's Spaceport in French Guiana, two government sources said.

The mishap has set back plans by the military to unify its fractured and overburdened communications network, and could hinder efforts to reinforce defenses in the East China Sea as Chinese military activity in the region escalates.

"When we need to shift units to the southwest and troops are moving down from the north, we need a stable communications link and this delay could affect that," a senior Defense Ministry official said on condition he not be identified because he was not authorized to talk to the media.