He said this to journalists following reports of mass civilian killings in the city of Bucha, Ukrinform reports with reference to NHK.
The prime minister noted that harming civilians violates international law and creates humanitarian problems. He also stressed that he was aware of the growing international criticism of these actions, and Japan should also condemn them.
Kishida also said that additional sanctions against those responsible for the killings were appropriate, and added that Japan would work closely with the international community to do what needed to be done.
As Ukrinform reported, Irpin, Bucha, Hostomel and the entire Kyiv region have been liberated from Russian invaders. Mass killings of civilians the Russian forces were recorded in towns and villages.
Bucha Mayor Anatoliy Fedoruk said that 280 people are buried in mass graves.