Japan said on Wednesday it was “regrettable” that a member of the Japanese military entered the Chinese embassy in Tokyo, after Beijing expressed shock at the incident.
The clash has further soured relations between Beijing and Tokyo, which have suffered since then comments by Japanese Prime Minister Sanae Takaichi for the self-governing island of Taiwan.
China mounted an outcry after the incident on Tuesday, in which Beijing’s foreign ministry said the man threatened to kill diplomats.
Senior Japanese government spokesman Minoru Kihara said: “It is truly unfortunate that a member of the Self-Defense Forces, who is expected to abide by the law, has been arrested on suspicion” of entering the embassy premises.
“The police are already conducting an investigation to clarify what happened and have implemented the necessary measures to strengthen the security” of the embassy, he said at a press conference.
“We will take the necessary steps to prevent any recurrence of such incidents,” he added.
Separately, a police spokeswoman told AFP that the suspect, Kodai Murata, 23, was arrested on Tuesday on suspicion of trespassing after he broke into the embassy at around 9:00 am (0000 GMT).
The suspect told police investigators that he “hoped to meet the ambassador to tell him to refrain from hard-line comments, and if this request was refused, 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.
Chinese foreign ministry spokesman Lin Jian said on Tuesday that Beijing was “deeply shocked” by the incident and had “submitted solemn representations and a strong protest to the Japanese side”.
Ties between Japan and China have soured since Takaichi suggested in November that Japan could intervene militarily in any Chinese attempt to take Taiwan.
China, which considers the democratic island part of its territory and has not ruled out annexation by force, was angered by the comments.
