Muto was told the step was “overtly hostile” because of Ukrainian drone use against Russia, and he was warned that Russia-Japan relations had reached an all-time low because of an “unfriendly policy towards Russia under the new cabinet of Sanae Takaichi,” the statement, dated Wednesday, said.

Japan’s foreign ministry didn’t immediately comment on the news.

In March, Terra Drone said it had made an investment in Amazing Drones LLC, which develops and manufactures interceptor drones in Ukraine. Terra Drone said it would develop an interceptor drone with the Ukrainian company and “promote the practical application of technical expertise cultivated in the country.”

Interceptor drones are designed to destroy threats such as missiles and other drones by ramming them or exploding near them.

The technology has helped Ukraine defend against Russian air-based attacks and has gained attention recently as an alternative to expensive missile interceptors used by the US and its allies to defend against Iranian drones and missile attacks.

Japan has mostly aligned with Western nations in sanctioning Russia since its full-scale invasion of Ukraine in 2022, an approach that prime minister Takaichi has pledged to continue.