In a significant escalation of tensions between China and Japan, a Chinese military surveillance plane breached Japanese airspace off the country's southwestern coast on Monday. This incident marks the first known incursion by China's military into Japan's territorial airspace, according to Japan's defense ministry.

The breach occurred when a Chinese reconnaissance aircraft briefly entered Japanese territory near Nagasaki Prefecture around 11:30 a.m. on Monday. In response, Japan's Self-Defense Force immediately put fighter jets on high alert and issued a warning to the Chinese aircraft, successfully forcing it to leave the airspace.

While Chinese planes have frequently appeared in international airspace around Japan, this is the first confirmed entry of a military aircraft into Japan's territorial airspace. Japan has been grappling with an increasing number of foreign aircraft encroachments over the past two decades. Last year alone, Japan's Self-Defense Force scrambled fighter jets in response to foreign planes on 669 occasions, which is more than three times the number of such responses compared to two decades ago.

According to Japan's Ministry of Defense, out of the 669 cases, 479 were in response to Chinese aircraft sightings. The incursion took place a day before Jake Sullivan, the White House national security adviser, is set to visit Beijing for talks with senior Chinese officials. The discussions are expected to focus on contentious issues such as the status of Taiwan and U.S. export controls of advanced technologies to China.

Military analysts suggest that this airspace violation by China could be a deliberate message challenging Japan's delineation of its territorial border. China asserts control over a large continental shelf in the East China Sea, with its outer edge extending close to the Danjo Islands area where the Chinese plane was spotted.

This recent airspace violation adds to a series of tension-heightening events between Japan and China. Last week, a Chinese newscaster deviated from the script on a radio news program by Japan's public broadcaster, asserting that the Senkaku Islands, controlled by Japan but claimed by China, belong to China. Furthermore, on the same day, graffiti using Chinese characters that appeared to read "toilet" was discovered at Tokyo's Yasukuni Shrine war-commemoration site.

Japanese officials wasted no time addressing this breach. They summoned Chinese Embassy representatives to a meeting on Monday evening, urging them to take necessary precautions to prevent future incursions into Japanese airspace, as stated by Japan's Ministry of Foreign Affairs.

While tensions between Japan and China continue to rise, the international community will closely watch the developments, particularly in light of the upcoming talks between the White House national security adviser and Chinese officials.