TOKYO: Japan said Wednesday it was "regrettable" that a member of its military broke into the Chinese embassy in Tokyo, while Beijing called for the perpetrator to be punished.
The Tuesday morning break-in has further soured relations between Beijing and Tokyo, which nosedived over Japanese Prime Minister Sanae Takaichi's comments on Taiwan.
Japanese police arrested 23-year-old Kodai Murata on suspicion of trespassing after he broke into the heavily guarded embassy grounds around 9:00 am (0000 GMT), a police spokesperson told AFP.
The suspect told investigators he was "hoping to meet the ambassador to tell him to refrain from making hardline remarks, and if that request was rejected, I wanted to surprise him by killing myself," the Yomiuri Shimbun reported, citing unnamed sources.
Japan's national broadcaster NHK said a knife was later found at the scene.
Japan's top government spokesman, Minoru Kihara, confirmed that the suspect was a member of the military.
"It is truly regrettable that a Self-Defense Forces member, who is expected to comply with the law, has been arrested on suspicion" of entering the embassy premises, Kihara told reporters.
"Police are already conducting an investigation to clarify what happened and have implemented necessary measures to strengthen security" of the embassy, he added.
Beijing, which lodged a formal protest against the incident, called for the perpetrator to be severely punished.
China's foreign ministry on Wednesday accused Japan of failing in its duties to protect diplomatic staff.
"The incident has seriously threatened the safety of embassy personnel, disrupted the peace and tranquillity of the embassy, and undermined the dignity of the embassy," ministry spokesman Lin Jian told a regular press conference.
"The Japanese side has failed... to uphold its special responsibility to protect the inviolability of the embassy and diplomatic representatives," he added.
Ties between the neighbours have deteriorated since Takaichi suggested in November that Japan might intervene militarily in any Chinese attempt to take Taiwan.
China, which regards the democratic island as part of its territory and has not ruled out force to annex it, was furious over the comments.