Japan suspends land-based Aegis Ashore missile defense deployment

"In view of the cost and time [required] for the deployment, we will halt the process," Defense Minister Taro Kono told reporters. "When considering the costs and the time frame, we have no choice but to decide it was not logical."

The system uses the Lockheed Martin Aegis Weapon System and the Raytheon Standard Missile for tracking and defending against incoming threats.

Japan intended to deploy it to counter threats from North Korean missiles, but increasing problems raised the $2.15 billion estimated cost to over $4 billion, including purchase cost and an expected 30-year use.

Two chosen sites for the land-based system have also run into difficulties: excessive work would be required to ensure that booster rockets fired from a location in western Japan would fall into the sea instead of residential areas, and the choice of an eastern location was flawed by improperly conducted geological surveys, forcing a reassessment of sites.

"For now, we will continue to rely on Aegis-equipped destroyers" to supply missile defense, Kono added. "Afterward, I will consider our options through the NSC [Japan's National Security Council]."

Japan has seven capable destroyers and is building an eighth. The country's current approach to missile defense involves a ship-based Aegis system designed to shoot down missiles in their post-boost phase of flight, and a land-based Patriot system to destroy them in their re-entry phase.

In the past, though, the government of Prime Minister Shinzo Abe has said the ship-based missile defense system is inadequate for defending Japan from North Korean missiles.

The sudden announcement caught Japanese politicians by surprise.

"It came out of the blue and I was surprised," said Tsugumasa Muraoka, governor of Yamaguchi prefecture, the location of the western defense site. Opposition party leaders said they will ask the government why the decision was made so close to Wednesday's end of the current parliamentary session.