Japan is imposing sanctions on Russia over its actions in Ukraine, Prime Minister Fumio Kishida said on Wednesday, terming Moscow's moves an unacceptable violation of Ukrainian sovereignty and international law, Reuters reported.

Japan's sanctions include prohibiting the issuance of Russian bonds in Japan and freezing the assets of certain Russian individuals as well as restricting travel to Japan, Kishida said.

"Russia's actions very clearly damage Ukraine's sovereignty and go against international law. We once again criticize these moves and strongly urge Russia to return to diplomatic discussions," he said.

"The situation remains quite tense and we will continue to monitor it closely."

Details of the sanctions will be worked out and announced over the coming days, he added.