Japan fires back at 'unsubstantiated' Chinese letter to UN

Japan's U.N. ambassador, Kazuyuki Yamazaki, was responding on Monday to a letter China's U.N. Ambassador Fu Cong wrote on Friday to U.N. Secretary-General Antonio Guterres.

Fu accused Japanese Prime Minister Sanae Takaichi of "a grave violation of international law" and diplomatic norms when she said in parliament this month that a Chinese attack on Taiwan could trigger a military response from Tokyo.

Yamazaki, in his letter, also addressed to Guterres, said Japan's fundamental policy was of "passive defense."

"Therefore, China's assertion that Japan would exercise the right of self-defense even in the absence of an armed attack is erroneous," he said.

Fu's letter was the strongest Chinese criticism yet of Takaichi, a conservative nationalist who took office last month, pointing to the worst bilateral tensions between China and Japan in years.

China says Takaichi's remark had "severely damaged" trade cooperation, while concerts of Japanese musicians in China have been abruptly canceled.

On Tuesday, Takaichi said she had spoken to U.S. President Donald Trump in what was their first phone call since the diplomatic bust-up with China, and that the U.S. leader had told her she could call him any time.

Takaichi also said Trump explained to her the recent state of U.S.-China relations, including his phone call with Chinese President Xi Jinping on Monday.

Trump has not commented publicly on the dispute between Japan - a key U.S. security ally - and rival superpower China, a silence that analysts say will be concerning to some officials in Tokyo.

China claims Taiwan, which sits just over 100 km (60 miles) from Japanese territory, and has not ruled out using force to take control of it. The island's government rejects Beijing's claim and says only Taiwan's people can decide their future.