
It is the first time Japan has specified the timing of the deployment.
The ministry announced the plan in 2022 to ramp up its air defences on the island, which already hosts a Japanese military base.
Japan’s defence minister Shinjiro Koizumi said at a regular press conference in Tokyo that the deployment on Yonaguni island would take place in the 2030 fiscal year, which ends in March of the following calendar year.
The comments come during a months-long row between Japan and China, with Beijing on Tuesday announcing that it was imposing export restrictions on dozens of Japanese firms that it said were involved in building up the country’s military.
Koizumi, who visited Yonaguni in November, said the ministry will hold a briefing for local residents next week on the island, located roughly 110 kilometres (68 miles) east of Taiwan and 1,900 kilometres southwest of Tokyo.
Japan’s conservative Prime Minister Sanae Takaichi suggested in November that Tokyo could intervene militarily in any attack on self-ruled Taiwan.
China views Taiwan as its territory and has not ruled out taking it by force.
Since Takaichi made the remark, Beijing has discouraged Chinese nationals from visiting Japan, which hit tourism, one of the pillars of the Japanese economy.
Beijing’s top diplomat Wang Yi said at the Munich Security Conference earlier this month that forces in Japan were seeking to “revive militarism”.
Takaichi told parliament on Friday that China was intensifying attempts to change the status quo “by force or coercion” in the East China Sea and the South China Sea and has said Japan needs to strengthen its defence capabilities.