BEIJING >> China’s dispute with Japan over tiny Japanese-controlled islands in the East China Sea is heating up again, with both sides accusing the other of infringing on their maritime territory.

China says the islands belong to it and refuses to recognize Japan’s claim to the uninhabited chain known as the Senkakus in Japanese and Diaoyu in Chinese. Taiwan also claims the islands, which it calls Diaoyutai, but has signed access agreements for its fishermen with Japan and does not actively take part in the dispute.

China routinely sends coast guard vessels and planes into waters and airspace surrounding the islands to harass Japanese vessels in the area and force Japan to scramble jets in response.

On Wednesday, a Chinese coast guard spokesperson said Chinese vessels had “expelled some Japanese vessels which had illegally entered the territorial waters.” The unidentified official said its moves were routine measures to safeguard sovereignty and maritime interests.

Japan’s coast guard on Thursday said Chinese coast guard vessels were violating Japanese territorial waters around the islands and have been repeatedly requested to leave and not to approach Japanese fishing boats operating in the area.

Unlike islands in the busy South China Sea, which China claims virtually in its entirety, the Senkaku/Diaoyu chain lying between Okinawa and Taiwan has little strategic importance. However, China has made it a cause celebre in its campaign to rally nationalism based on memories of Japan’s brutal invasion and occupation of much of China that ended in 1945.

Meanwhile, South Korean President Yoon Suk Yeol and Japanese Prime Minister Fumio Kishida were meeting in Tokyo Thursday for talks underscoring their shared sense of urgency to form a united front on North Korea and China with their mutual ally, the United States.

Chinese intrusions by China’s military vessels into waters around the Islands featured in wide-ranging January discussions in Washington between President Joe Biden and Japanese Prime Minister Fumio Kishida.

Those talks came as Japan is increasing defense spending dramatically and looking to build security cooperation with allies in a time of provocative Chinese and North Korean military action.

The U.S. is also bolstering alliances in the Indo-Pacific to meet new threats, including providing Australia with nuclear-powered submarines, gaining increased access to Philippine bases and boosting defense cooperation with Taiwan, the self-governing island democracy China claims as its own territory to be brought under its control by force if necessary.