TOKYO — Japan is preparing to deploy its first batch of domestically developed long-range missile s, with their launchers arriving at an army camp Monday as the country accelerates its offensive capability in response to rising challenges in the region.

The upgraded Type-12 land-to-ship missiles will be deployed at Camp Kengun in Japan’s southwestern prefecture of Kumamoto by the end of March, completing the process of deployment, Chief Cabinet Secretary Minoru Kihara said.

Army vehicles carrying their launchers and other equipment arrived early in the morning in a highly secretive mission criticized by local residents who protested outside the camp.

Opponents have complained about the lack of transparency and said the deployment would instead escalate tension and make the missiles the target of attacks.

The Defense Ministry last year moved up the schedule of the missiles’ deployment by one year as Japan accelerates a military buildup in the southwestern region as China escalates tension around Taiwan, the self-governing island Beijing claims as its own.

The upgraded Type-12 missile, developed and produced by Mitsubishi Heavy Industries, has a range of about 1,000 kilometers (620 miles) and can reach mainland China, a significant extension from the 200-kilometer (125-mile) range of the original.

It will be deployed next at Camp Fuji in Shizuoka, west of Tokyo, later this year.

Japan considers China a growing security threat and has pushed a military buildup on southwestern islands near the East China Sea. It has deployed PAC-3 interceptors and midrange surface-to-air missiles on many of the islands, including Okinawa, Ishigaki and Miyako.

Defense Minister Shinjiro Koizumi last month said Japan will deploy the midrange SAMs on Japan’s westernmost island of Yonaguni, just east of Taiwan, by March 2031.

Tensions have escalated further since Prime Minister Sanae Takaichi’s comment soon after taking office that any Chinese military action against Taiwan could be grounds for a Japanese military response.

Takaichi has pledged to revise security and defense policy by the end of the year and seeks to further bolster Japan’s military with unmanned combative weapons and long-range missiles.

Her government is also set to scrap restrictions on lethal arms exports in the coming weeks to promote the development of Japan’s defense industry and cooperation with friendly nations, based on a proposal recently submitted by her party and its governing coalition partner.