Japan Thursday lodged an official protest with China, after it spotted a Chinese frigate in waters surrounding flashpoint islands in the East China Sea, the first such incursion in more than a year.
The 4,000-ton Jiangkai-II class frigate was spotted at 11 a.m. sailing near the contested waters, known as the Senkaku in Japan and Diaoyu in China, according to the South China Morning Post.
Vice Foreign Minister Shinsuke Sugiyama summoned Chinese Ambassador to Japan Cheng Yonghua on Thursday to express his grave concern regarding the issue and protest the frigate's entry into the area, the Japanese Foreign Ministry said. "We urge the Japanese side not to create artificial incidents around Diaoyu and make efforts jointly with China to improve bilateral relations in the spirit of a consensus reached in 2014", Chinese Foreign Ministry's spokesman Lu Kang said Thursday.
China's timing is equally unusual given the fact that Japan is hoping to improve relations between both nations.
After all, for Japan, the Senkaku area is part of protecting smaller islands and islets throughout the Okinawa region. On Thursday, Japan issued a warning to China to stand down after a military warship and submarine were seen near the disputed waters in East China Sea.
Another foggy night ahead with further weather warning issued
Visibility could drop to 100 metres in some places bringing risky driving conditions and hindering flight take offs, he added. It adds: "Strong winds create the potential of blizzard conditions and drifting of lying snow".
The submarine's presence was confirmed by a Japan Maritime Self-Defense Force escort ship and a P-3C aircraft, the statement said. The submarine left the zone on Thursday morning, but again sailed into the zone northeast of Taisho Island in the Japanese-administered Senkaku chain later.
China routinely rejects Japanese criticism of such patrols, saying its ships have every right to operate in what China calls its territorial waters.
Japanese Prime Minister Shinzo Abe responded to the incidents Thursday by giving instructions to prepare for all possible contingencies and to coordinate closely with the US, according to a statement released by his Cabinet.
Japan was monitoring the submarine, but would refrain from releasing details, including its identity, Japan's Chief Cabinet Secretary Yoshihide Suga told a regular briefing.
Maritime confrontations and jet interceptions between China and Japan have become commonplace in recent years, especially around the Senkakus.