Japan's Chief Cabinet Secretary Hayashi Yoshimasa has commented on the death sentence in China handed down to a man charged in connection with a knife attack on a bus carrying Japanese schoolchildren.

Hayashi said at a news conference on Thursday that the Chinese court said the man killed and wounded three people as he got sick of living because of his debts.

He added that the court described the man's crime as extremely heinous and posed a serious threat to society. Hayashi also said the court made no mention of Japan in the ruling.

Hayashi went on to express once again his deepest regret over the loss of Hu Youping, a Chinese female bus attendant who was killed in the incident. He also said he wants to again convey his heart-felt sympathies to a Japanese mother and her child who were injured.

Hayashi said the crime of killing and hurting three innocent people, including a child, should never be forgiven.

He added that ensuring the safety of Japanese citizens who visit or live in foreign countries is one of the government's important duties. He said the government will continue to strongly urge China to ensure their safety.

China's Foreign Ministry Spokesperson Mao Ning also referred to the ruling during a news conference on Thursday. She noted that judicial institutions hold hearings based on law and China will continue to take measures to protect the safety of foreigners.