Previously, China had cautioned Japan regarding such an action.

Japan is negotiating the opening of a NATO office / © Freepik
Due to the Russian incursion into Ukraine, Japan is engaged in discussions with NATO concerning the establishment of an office, the first of its kind on the Asian continent.
This was communicated by Hayashi Yoshimasa, the nation’s Foreign Minister, during an exclusive exchange with CNN on Wednesday, May 10.
According to his statement, the Russian invasion of Ukraine bears ramifications extending considerably beyond Europe, which has compelled Japan to reassess its security within the region.
“The rationale behind our deliberations stems from the heightened global instability following Russia’s aggression towards Ukraine. The events unfolding in Eastern Europe are not confined to that region; they exert a direct influence on the situation prevailing here in the Pacific. Consequently, collaboration between ourselves and NATO is gaining increased significance,” he articulated.
The writers of the article posit that “the inauguration of a NATO liaison office within Japan would represent a noteworthy occurrence for the Western alliance, unfolding against a backdrop of escalating geopolitical fissures. It is anticipated to elicit censure from the Chinese administration, which had previously advised against a similar step.”
James Appathurai, a representative for NATO, provided remarks on this information to CNN.
“Concerning intentions to inaugurate a liaison office in Japan, we will refrain from divulging specifics about ongoing discussions amongst NATO allies. Our cooperation with Japan has a lengthy history,” he stated.
It is worth mentioning that the Russian-Japanese border lies between Russia in the north and Japan in the south. Its entire length is maritime. Japan asserts that the Russian-Japanese boundary runs through the Frisian Strait, and the islands located southwest of this strait (Itupup, Kunashir, Shikotan, and the Habomai group of islands) are currently under Russian occupation.
As a reminder, the EU and Japan are against the US proposal to restrict exports to Russia.