TOKYO • Japan will pump in US$500 million (S$682 million) to boost maritime security in East Asia between this year and 2019, Foreign Minister Taro Kono announced on Thursday.

This includes a plan to provide 16 patrol vessels to Vietnam and the Philippines, national broadcaster NHK quoted the Foreign Ministry as saying, adding the aid was not aimed against any specific country.

Japan has been active in capacity-building projects in the region.

While it is not party to the territorial disputes in the South China Sea, it hopes to demonstrate its ability to protect the existing world order.

Yesterday, the Foreign Ministry lodged a protest with the Chinese embassy in Tokyo after four Chinese patrol ships briefly entered Japan's territorial waters near contested islets in the East China Sea on the same day - the 21st such occurrence this year. Japan administers the disputed Senkaku islands in the East China Sea, which China claims and refers to as the Diaoyu islands.

This came hours after the United States' and Japan's defence and foreign ministers in Washington reaffirmed their concerns over maritime security in the East and South China seas. US Secretary of State Rex Tillerson had stressed that the Senkaku islands fell well within the scope of the US-Japan bilateral security treaty.

Dr Narushige Michishita from the National Graduate Institute for Policy Studies said: "If left to its own devices, China might think it could get away with whatever it does, but with the US' and Japan's repeated demonstrations of their commitment, China might have realised it has to be reasonable."

Walter Sim