The Abe administration has approved the development and export by Japanese companies of some computer system components for the Aegis system that can intercept ballistic missiles.
It was the fourth approval by the National Security Council since the ban on overseas transfers of defense equipment was revised in April 2014 to pave the way for more arms exports.
The latest approval will allow the companies to participate for the first time in the production of the U.S.-developed Aegis computer system for warships that collects and processes data for fast responses to enemy attacks.
The components covered by the approval include Mitsubishi Heavy Industries Ltd. software for command post displays and Fujitsu Ltd. parts for tablet computers.
The components are superior in performance and cheaper than their U.S. equivalents and have been recommended by the United States for the Aegis system.
The software will be registered in a database managed by the U.S. Defense Department and made available to Australia, South Korea, Spain and Norway, which plan to introduce Aegis-equipped warships.
The government plans to order one Aegis-equipped destroyer this fiscal year and another by fiscal 2018. The vessels will be built in Japan with the Aegis computer system imported from the U.S.