Defense Minister Takeshi Iwaya on Sunday highlighted Japan’s resolve to defend its far-flung territory amid China’s maritime assertiveness by touring a newly opened Ground Self-Defense Force base on Miyako Island.

“The Miyako Island camp is on the front lines of our country’s defenses. We are seeing steady progress over the defense of the southwestern region,” Iwaya told GSDF members on the islet located some 290 kilometers southwest of Okinawa’s main island.

Miyako Island sits around 210 km from the Japan-controlled Senkaku Islands in the East China Sea, which China claims and calls Diaoyu. Chinese government ships have repeatedly entered Japanese waters around the Senkakus, creating tensions.

The GSDF is gearing up to fill what is considered a defense vacuum in the waters around Okinawa, with Japanese troops having been stationed only on the prefecture’s main island until recent years.

On Miyako Island, a 380-member security unit was deployed to a camp established on March 26. Missile units are also expected to be installed as early as 2020, with the total number of troops there to eventually increase to 700 or 800.

Some of the approximately 54,000 residents of the island group have expressed opposition to the GSDF deployment.

Iwaya has recently admitted that ammunition, such as mortar rounds, have been in storage on the camp site despite authorities having told locals that only guns and flares are kept. On Sunday, he apologized to Miyakojima Mayor Toshihiko Shimoji and a representative of local residents over the incident.

“Our explanation was insufficient. I’m very sorry,” Iwaya said.

The ammunition has been temporarily removed from the island to address safety concerns among residents. It will be brought back once an ammunition depot, which is under construction in a different part of the island, is completed, according to the Defense Ministry.