Russia-controlled Kunashiri Island is seen in the distance from the Shiretoko Peninsula on Hokkaido, Japan. (Seth Robson/Stars and Stripes)

TOKYO — A suspected Russian helicopter entered Japanese airspace near Hokkaido, the northernmost of Japan’s four main islands, on Tuesday, according to the Ministry of Defense.

The Japan Air Self-Defense Force scrambled fighters around 12:44 p.m. in response to the incursion off the Nemuro Peninsula in the island’s northeast, the ministry said in a news release Tuesday. It did not specify the helicopter’s type.

Tokyo complained to Moscow through diplomatic channels and demanded it take measures to prevent further incursions, a spokesman for Japan’s Joint Staff told Stars and Stripes by phone Wednesday.

U.S. Indo-Pacific Command did not comment on the situation, according to an email Wednesday from spokeswoman Kirah Wurst.

The incident marked the first time a Russian helicopter has entered Japanese airspace since March 2022. One flew near Hokkaido in March 2022, after Japan pledged $200 million to support Ukraine and joined the U.S. and several European countries imposing economic sanctions on Russia.

That month, 16 Russian warships were spotted near Japanese waters, with a group of 10 sailing through the Tsugaru Strait, which separates Hokkaido from Honshu, Japan’s largest island. The strait is about 30 miles wide at its narrowest point.

“The Russian flotillas are a show of force designed to warn Japan against imposing further sanctions,” James Brown, an international affairs expert at Temple University’s Japan campus told Stars and Stripes at the time.

“As Japan imposes further sanctions, we can expect to see more of this,” he said.

The southernmost islands of the Kuril chain north of Hokkaido have been the subject of a territorial dispute between Tokyo and Moscow since the end of World War II. The Kurils stretch from northern Japan to Russia’s Kamchatka Peninsula.