Japan has called on China to curb drone flights near the disputed Senkaku Islands in the East China Sea by communicating to Beijing its "interest" in a Chinese drone flight in the area on Monday, a senior Foreign Ministry official said Tuesday.
On the eve of the first anniversary of the purchase by the Japanese government of a major portion of the islands, Chief Cabinet Secretary Yoshihide Suga said Japan has the option of stationing government personnel on the uninhabited islands to strengthen its control over them.
At a news conference, the top government spokesman added, however, "We should think from a strategic viewpoint about under what circumstances we should consider that."
And in another sign of mounting tensions over the islands, eight China Coast Guard vessels temporarily intruded into Japanese territorial waters around the islands on Tuesday, the Japan Coast Guard said.
Vice Foreign Minister Akitaka Saiki later summoned Chinese Ambassador to Japan Cheng Yonghua to the ministry to lodge a protest over the largest number of Chinese government vessels to enter the waters on a single day this year. Eight Chinese vessels also entered the waters on April 23.
With Saiki demanding that all the vessels leave the waters immediately, Cheng repeated the Chinese government's claims to the islands, the ministry said.
Amid the rising tension, Foreign Minister Fumio Kishida sought Tuesday to keep the situation surrounding the islands under control.
"While relations between Japan and China are at a difficult stage, we must work hard to prevent individual issues from affecting overall ties between the two countries," Kishida told reporters.
In Beijing, the Chinese Foreign Ministry reacted sharply to Suga's remarks on the possibility of stationing Japanese government personnel on the Senkaku Islands, saying if Japan takes "provocative" actions, it must "accept the consequences."
"We are severely concerned about the remarks made by the Japanese side," Chinese Foreign Ministry spokesman Hong Lei said at a news conference. "We are resolute and determined to safeguard our territorial sovereignty. We will not tolerate any provocative actions against China's sovereignty."
Speaking to reporters in Tokyo, Defense Minister Itsunori Onodera said the Self-Defense Forces are on heightened alert following the Chinese drone flight, and will maintain this posture as Wednesday marks the first anniversary of the island purchases by the government.
The Foreign Ministry had conveyed its "interest" in the flight to the Chinese Embassy in Tokyo on Monday, after the drone flew within Japan's air defense identification zone where aircraft need to identify themselves and provide flight routes and other information.
A senior ministry official said that while Monday's flight did not violate international law, Tokyo needs to remain vigilant about similar maneuvers.
The aircraft believed to be a drone flew near the islands on Monday morning, prompting the Air Self-Defense Force to scramble fighter jets. Later Monday, China's defense ministry admitted in a statement that the aircraft was a People's Liberation Army drone.
The Senkaku Islands are at the heart of the fraying of Japan's ties with China, which claims the islands and calls them Diaoyu. The purchase by Japan's central government from a private owner on Sept. 11, 2012, sparked widespread demonstrations in China and sent Japan-China relations to their lowest point in years.