NATO chief Mark Rutte and Japan’s defence minister shared their “grave concerns” about recent joint patrols by Chinese and Russian aircraft, Tokyo said.
The incident on Tuesday came as Japan-China relations worsen after comments by Prime Minister Sanae Takaichi about Taiwan that enraged Beijing.
“Both sides shared their grave concerns over this incident and concurred to closely communicate with each other,” the Japanese defence ministry said late Wednesday.
The statement followed a 15-minute video conference between Rutte and Defence Minister Shinjiro Koizumi, the ministry said.
Koizumi also briefed Rutte about another recent incident that involved Chinese aircraft locking its radar onto Japanese planes near Taiwan, the statement added.
According to Tokyo, two Russian Tu-95 nuclear-capable bombers on Tuesday flew from the Sea of Japan to rendezvous with two Chinese H-6 bombers in the East China Sea, then conducted a joint flight around the country.
Japan scrambled aircraft in response.
South Korea said Tuesday that Russian and Chinese warplanes also entered its air defence zone, with Seoul also deploying fighter jets.
Beijing confirmed later on Tuesday that it had organised drills with Russia’s military according to “annual cooperation plans”.
Moscow also described it as a routine exercise, saying it lasted eight hours and that some foreign fighter jets followed the Russian and Chinese aircraft.
Takaichi suggested last month that Japan would intervene militarily in any Chinese attack on Taiwan, which Beijing claims as its own and has not ruled out seizing by force.
