TOKYO/BEIJING, June 12 (Reuters) - Chinese fighter jets flew unusually close to Japanese military patrol planes over the Pacific last weekend, Tokyo said, after it spotted two Chinese aircraft carriers simultaneously deployed in the waters for the first time.
While Beijing said its military activities were "fully in line with international law" and asked Japan to stop its "dangerous" reconnaissance, Japanese and U.S. officials have seen the jets' actions as another sign of the Chinese military's growing assertiveness beyond its borders.
Tokyo has "expressed serious concern ... and solemnly requested prevention of recurrence" to Beijing, Chief Cabinet Secretary Yoshimasa Hayashi said on Thursday, referring to the June 7-8 incidents in which Japan said Chinese jets flew as close as 45 meters (148 feet) to Japanese planes.
On Saturday, a Chinese J-15 jet from the aircraft carrier Shandong chased a Japanese P-3C patrol aircraft for about 40 minutes, Japan's defense ministry said. On Sunday, a J-15 chased a P-3C for 80 minutes, crossing in front of the Japanese aircraft at a distance of only 900 meters, it added.
A spokesperson at the ministry's Joint Staff Office declined to disclose whether the same planes were involved in the incidents on both days.
The P-3C aircraft, belonging to a Japan Maritime Self-Defense Force fleet based in the island of Okinawa, were conducting surveillance over international waters in the Pacific, according to the ministry.
"Such abnormal approaches by Chinese military aircraft could potentially cause accidental collisions," the ministry said in a Wednesday statement, attaching close-up images of the missile-armed J-15 jet it took on Sunday. There was no damage to the Japanese planes and crew, it added.
In response, China's foreign ministry spokesperson Lin Jian told a regular press conference that "the close-in reconnaissance by Japanese ships and planes of China's normal military activities is the root cause of the risk to maritime and air security."
"The Chinese side urges the Japanese side to stop such dangerous behavior."
Earlier this week, Tokyo said the Shandong and another Chinese carrier, the Liaoning, were conducting simultaneous operations in the Pacific for the first time. Beijing has said the operations were a "routine training" exercise that did not target specific countries.
The Chinese presence in the sea and airspace in the southeast of the Japanese island chain has put Tokyo and its ally Washington on heightened alert, as Japan pursues its biggest military buildup since World War Two in the wake of the intensifying security environment in East Asia, including over Taiwan.
"Our sense of urgency is growing," General Yoshihide Yoshida, Chief of Staff of Japan's Joint Staff, told a briefing.
"As evident in the South China Sea, the Chinese military has unilaterally changed the status quo through force wherever their military influence extends ... we will maintain a deterrent posture not to allow these actions normalized," added Yoshida, Japan's highest-ranking uniformed officer.
"The recent dangerous maneuver by a Chinese fighter jet that put Japanese crewmembers' lives in peril must be another of Beijing's 'good neighbor' efforts," U.S. Ambassador to Japan George Glass said in an X post.
"Whether it's harassing Philippine ships, attacking Vietnamese fishermen, or firing flares at Australian aircraft, Beijing knows only reckless aggression," Glass added, citing recent incidents in the South China Sea.
In 2014, Tokyo said it spotted Chinese military aircraft flying as close as 30 meters to its military aircraft over the East China Sea and protested to Beijing.