Updated

Japan's Cabinet has approved a plan to purchase a set of costly land-based U.S. missile combat systems to step up the country's defense capability amid escalating threats from North Korea.

Tuesday's approval will allow the Defense Ministry to buy two Aegis Ashore systems to add to Japan's current two-step missile defense consisting of Patriot batteries and Aegis-equipped destroyers.

The purchase would add to growing defense costs as Prime Minister Shinzo Abe's government pushes to allow Japan's military a greater international role and boost its missile combat capability.

Defense officials say two Aegis Ashore units can cover Japan entirely and could cost around 200 billion yen ($1.8 billion), though they have not released exact figures. The deployment is planned for 2023.