The move comes after Russian officials accused Japan’s consul in the city of Vladivostok of espionage, detaining him for three hours before removing him from the country.

Consul Tatsunori Motoki was declared persona non grata and returned home last week. Japan maintains his innocence. He was first detained in late September.

“There is no fact that the consular officer conducted an illegal activity as Russia alleges. The acts by Russia, including a detention of the consular officer and an intimidating interrogation, constitute a clear and serious violation of the Vienna Convention on Consular Relations and the Japan-Soviet Consular Convention. It is extremely regrettable, and absolutely unacceptable,” Japan’s vice-minister of foreign affairs MoriI Takeo said in a statement on the ministry’s website.

“In addition, it is an unbelievable act that Russia declared the consular officer as persona non grata, and Japan lodges once again a strong protest against it.”

Takeo also called the retaliatory move an “appropriate measure in response to the measures taken by Russia.”

Galuzin, the Russian ambassador to Japan, said the diplomat “did not engage in activities violating his authority” in a statement obtained by Kyodo News.

Japan’s diplomatic ties with the Kremlin have cooled significantly since it aligned itself with the West after Russia’s invasion of Ukraine.