Marles, who is in Japan to inspect shipyards after Australia signed a $10 billion deal to buy 11 warships, expressed his concern about the incident just a week after he revealed the Australian Defence Force was tracking the course of a Chinese flotilla heading south in the Philippine Sea.
Loading
The defence minister is flying to Washington, DC, on Monday where he and Foreign Minister Penny Wong will have high-level security talks with US War Secretary Pete Hegseth and Secretary of State Marco Rubio.
The weekend encounters near islands close to territory claimed by both Japan and China are the most serious run-ins between the two militaries in years, and are likely to further escalate tension between the neighbours.
Relations have already soured after Prime Minister Sanae Takaichi warned that Japan could respond to any Chinese military action against Taiwan if it also threatened Japan’s security.
China claims democratically governed Taiwan, and has ramped up military and political pressure against the island whose government rejects Beijing’s territorial claims. Taiwan lies just 110 kilometres from Japan’s westernmost island, Yonaguni.
Japan hosts the biggest overseas concentration of U.S. military power, including warships, aircraft and troops, with much of that contingent, including thousands of U.S. Marines, based in Okinawa.
Marles speaks during a press conference in Tokyo on Sunday.Credit: AP
The US State Department and the US Embassy in Tokyo did not immediately respond to requests for comment on Japan’s claims about China’s use of radar.
Japan said the Chinese jets involved in the two incidents were launched from China’s Liaoning aircraft carrier, which was manoeuvring south of the Okinawan islands with three missile destroyers.
On Thursday, China was deploying a large number of naval and coast guard ships across East Asian waters, which at one point numbered more than 100, Reuters reported, citing sources and intelligence reports.
Loading
Taiwan’s government described that build-up as posing a threat to the Indo-Pacific region. Japan said it was monitoring Chinese activity closely.
On Sunday, Taiwan’s coast guard said it was monitoring drills by three Chinese maritime safety ships on the western side of the Taiwan Strait’s median line, but said the situation in the waters surrounding Taiwan was currently “normal”.
Chinese state media said the search-and-rescue drills were in the central waters of the strait, patrolling “high-traffic areas, and areas with frequent accidents”.
Taiwan’s coast guard said China was using “misleading and false wording” about what it was doing, with the aim of harassing Taiwan and carrying out psychological warfare.
Loading
China says it alone exercises sovereignty and jurisdiction over the strait, a major trade route for about half the world’s container ships. The US and Taiwan say the strait is an international waterway.
With Michelle Griffin
Get a note directly from our foreign correspondents on what’s making headlines around the world. Sign up for our weekly What in the World newsletter.
