Japan plans to upgrade five airports and 11 ports, designating them for use by the country's defense forces and coast guard in case of military emergencies, a government source said Wednesday, with concerns lingering over China's maritime assertiveness and a potential conflict over Taiwan.

Nearly half of the 16 commercial facilities, which include Naha and Nagasaki airports, are located in either Okinawa Prefecture or the southwestern main island of Kyushu, apparently reflecting Japan's efforts to bolster defense around its far-flung southwest islands.

The plan is expected to be approved soon at a meeting of related ministers, paving the way for the project to commence in the next fiscal year, starting April. An allocation of ¥35 billion ($230 million) is anticipated for the first year.