Japan has decided to suspend a plan to deploy the U.S-developed Aegis Ashore missile defense system, designed to counter the threat of North Korean ballistic missiles, due to technical problems and ballooning costs, Defense Minister Taro Kono said Monday.

In an abrupt announcement, Kono said it would be difficult to ensure that the rocket booster of an interceptor missile would land in a Self-Defense Forces training area or the sea, as promised, without hardware modifications.

"In view of the cost and (more) time (needed) for the deployment, we will halt the process," Kono told reporters, adding that he informed Prime Minister Shinzo Abe on Friday of the decision related to the defense system that was expected to go into operation in fiscal 2025 at the earliest.