A helicopter apparently operated by the Russian military violated Japanese airspace near Hokkaido on Wednesday, with the Defense Ministry saying it had scrambled fighter jets in response, as Tokyo watches with concern Moscow’s moves amid the ongoing conflict in Ukraine.

The ministry said the helicopter entered Japan’s territorial airspace off the Nemuro Peninsula, on the eastern coast of the nation’s northernmost prefecture. The ministry did not give an exact location of the flight, but the peninsula is located just kilometers from the closest of four islands northeast of Hokkaido that Russia occupies and Japan claims.

According to the ministry, the Russian military has used exercises in the Sea of Okhotsk and other areas to highlight its capabilities to operate in both the European and Asian theaters simultaneously amid the war in Ukraine.