The United States has for the first time criticised China for aiming radars at Japanese military aircraft during a training exercise last week, incidents that the Asian neighbours have given differing accounts of amid escalating tensions.

The run-in near Japan’s Okinawa islands comes after Japanese Prime Minister Sanae Takaichi triggered a dispute with Beijing last month with her remarks on how Tokyo might react to a hypothetical Chinese attack on Taiwan.

China claims democratically governed Taiwan and has not ruled out using force to take control of the island, which sits just over 100 km (62 miles) from Japanese territory and is surrounded by sea lanes that Tokyo relies on.

“China’s actions are not conducive to regional peace and stability,” a State Department spokesperson said late Tuesday, referring to the radar incident.

“The US-Japan Alliance is stronger and more united than ever. Our commitment to our ally Japan is unwavering, and we are in close contact on this and other issues.”

Japan Chief Cabinet Secretary Minoru Kihara welcomed the comments, saying they “demonstrate the strong US-Japan alliance”.

China’s foreign ministry did not immediately respond to a request for comment.

Japan late on Tuesday scrambled jets to monitor Russian and Chinese air forces conducting joint patrols around the country.

MOST SERIOUS INCIDENT IN YEARS

The Chinese fighter jets aiming their radars at the Japanese planes on Saturday was the most serious run-in between the East Asian militaries in years.

Such moves are seen as a threatening step because it signals a potential attack and may force the targeted plane to take evasive action. Tokyo blasted the moves as “dangerous”.

Beijing, however, said that the Japanese aircraft had repeatedly approached and disrupted the Chinese navy as it was conducting previously announced carrier-based flight training east of the Miyako Strait.

Speaking to reporters in Taipei on Wednesday, Taiwan President Lai Ching-te said China’s drills were “very inappropriate behaviour”.

“We also call upon China to demonstrate the responsibility befitting a major power. Peace is priceless; war has no winners. Peace must be fostered by all parties, and China shares this responsibility,” he said.

Relations between Asia’s two largest economies have soured sharply since Takaichi told parliament last month that a Chinese attack on Taiwan could amount to a “survival-threatening situation” and trigger a potential military response from Tokyo.

Beijing has demanded she retract the remarks, accused Tokyo of threatening it militarily and advised its citizens not to travel to Japan.

US Ambassador to Japan George Glass has publicly expressed support for Japan in several social media posts since the diplomatic dispute began, but President Donald Trump and other senior US officials have remained silent.

Trump, who plans to visit Beijing next year for trade talks, telephoned Takaichi last month, urging her not to escalate the dispute, people with knowledge of the matter told Reuters.