Japan is to begin building a new class of light patrol ships for the Maritime Self-Defence Forces in 2020, the defence ministry has confirmed to the South China Morning Post.
The new warships will be designed to carry out reconnaissance and surveillance missions within Japan's territorial waters, freeing up the destroyers that have been used in recent years to patrol waters close to the Diaoyu archipelago, which Japan controls and refers to as the Senkaku Islands but which both Beijing and Taipei claim sovereignty over.
An official in the ministry's press office confirmed that the new vessels' primary tasks would be patrolling, although no decision has been made on where they will be based or how soon they will be deployed. Similarly, the official said, no decision has been announced on a budget or the companies that will build the vessels, which were first proposed in the National Defence Programme Guidelines approved by the government in December.
The guidelines say the defence force will operate patrol ships but do not specify areas of operation.
There is little debate, however, over the biggest threat that Tokyo perceives to its territorial integrity.
"Japan sees China as a rising threat to its maritime interests and its inherent territory, and that means primarily Okinawa and the Senkaku Islands," said Jeff Kingston, director of Asian Studies at the Tokyo campus of Temple University.
"Deploying more ships in that area is designed to send a message to Beijing that Japan is not going to acquiesce and will continue to press and defend its claims", he told the South China Morning Post.
"But neither side is going to back down over the question of the islands, so we have this cat-and-mouse situation in which, I suspect, China will continue to probe and test and assert its own claims", he said.
"And every time a Chinese ship intrudes into Japanese territorial waters around those islands, Beijing will say that it is asserting its rights, and then Japan will respond in kind.
"Both sides are putting their markers down and the waters there are a potential flashpoint."
The potential for a minor incident or an accidental clash escalating rapidly is clear from an incident in September 2010, Kingston said, in which the Chinese trawler Minjinyu 5179 collided with a patrol vessel from the Japanese coastguard within Japan's territorial waters around the disputed islands.
The subsequent arrest of the captain of the Chinese vessel, Zhan Qixiong, caused a major diplomatic rift between Tokyo and Beijing that saw China halt exports of rare earth minerals to Japan. The 14 crew of the vessel were returned to China after six days, with Zhan released after 17 days in custody.
"There is clearly the potential for something like that happening again, but I do believe that both sides have an interest in not seeing an incident escalating," said Kingston.
Under the Japanese government's plan, work on the first three ships in the new class will begin in the 2020 financial year and Tokyo aims to be able to deploy 12 ships within a decade. Government sources told the Yomiuri newspaper that the new ships would have a displacement of around 1,300 tonnes and a crew of 30.
Having the new ships will permit the larger destroyers that are presently patrolling the area to be dispatched elsewhere for other operations.
Coinciding with the announcement of plans for new warships, the Japanese coastguard has acquired a new Airbus H225 Super Puma helicopter. The long-range, twin-engined aircraft is to be used for security enforcement and territorial monitoring activities, and will also be put into use in the event of a natural disaster.