The Japan Coast Guard is planning to deploy patrol ships to the Ogasawara Islands, about 1,000 km south of Tokyo, with the aim of strengthening its capabilities of cracking down on illegal foreign fishing boats, a government official said Wednesday.

Under the plan, an as-yet undecided number of patrol boats will be deployed to Chichijima, the main island in the Ogasawara chain — an archipelago of about 30 islands — within a few years.

Given that the waters around the islands account for about 30 percent of Japan's exclusive economic zone, the government decided it should quickly boost the response capability of the Ogasawara coast guard station, which only has one surveillance boat.

Coral fishing boats from China unlawfully operated in the ocean around the islands in 2014 and 2015, with the number of boats occasionally reaching more than 200 in a single day, forcing the small-scale coast guard station to call for support from other stations.

Coral poaching boats sailing from Chinese ports have become almost nonexistent in the area over the past few years after Tokyo discussed the issue with Beijing through diplomatic channels, but a coast guard official stressed the possibility of them returning and the need to be prepared.

The plan also calls for nine state-of-the-art patrol ships to be deployed to Okinawa Prefecture's Miyako Island — which Tokyo views as a key point in guarding waters around the disputed Senkaku Islands — and Ishigaki Island, also in the prefecture. Construction is set to begin this fall on Miyako Island for a shooting range to train coast guard personnel.

The uninhabited Senkaku Islands in the East China Sea are controlled by Japan but also claimed by China and Taiwan, where they are known as Diaoyu and Tiaoyutai, respectively.