Japan is preparing to salvage the mystery ship that sank last month in a battle with coast guard vessels in the East China Sea, Chikage Ogi said Tuesday.

"The coast guard is preparing a schedule to raise the suspicious ship. For the time being we want to gather information by using a robot to take photos," the minister of land, infrastructure and transport said at a news conference.

"Since the suspicious ship sank in the Chinese exclusive economic zone, we want to notify China (about the schedule) through the Foreign Ministry," she said.

The coast guard is expected to use a remote-control underwater TV camera to judge whether the vessel can be salvaged. It will check the ship's conditions and whether it contains any dangerous materials. The wreck is about 90 meters under the surface.

Meanwhile, Defense Agency chief Gen Nakatani said Tuesday that the Maritime Self-Defense Force ended its search for the ship's missing crew members Monday.

"We want to stay on alert and monitor our country's coastal regions," Nakatani said.

The unidentified ship, believed to be from North Korea, sank Dec. 22 when a prolonged pursuit by coast guard patrol boats, which had been attempting to disable and board it, turned into a full-scale firefight.

All 15 crew members went missing after the ship sank, and two of their bodies were later recovered. The rest of the crew is assumed to have died.