The Coast Guard announced Wednesday that it has been tracking what it believes is a Russian intelligence-gathering ship over “recent weeks” off the coast of the Hawaiian Islands and released video of the ship refueling at sea with another Russian vessel.

“While foreign military vessels may transit freely through the U.S. economic exclusive zone, as per customary international laws, foreign-flagged military vessels have often been observed operating and loitering within Coast Guard District Fourteen’s area of response,” the service said in a news release. The Coast Guard’s District 14 is headquartered in Honolulu and encompasses operations across Oceania. A spokesperson for District 14 confirmed that there were two ships that were believed to be conducting a refueling operation but said he could offer no other details.

During the Cold War, Russian military vessels commonly lingered off the coasts of American states and territories, but after the collapse of the Soviet Union these operations became far less common. In 2012 the Russian navy sailed as an invited guest to Hawaii to participate in Exercise Rim of the Pacific, the world’s largest recurring international naval war game.

But since the March 2014 seizure of the Crimean region of Ukraine by Russian military forces, the Russian navy aggressively began stepping up operations globally. American fishermen sailing in the northern Pacific near Alaska have reported increasing interactions with Russian military ships and aircraft that some have described as confrontational.

The Kremlin has longstanding military ties and arms trading deals with several countries across Asia and maintains its own sizeable Pacific fleet. The Vladivostok-based intelligence gathering ships Kareliya and Pribaltika have been spotted multiple times near Hawaii since the Pribaltika stopped in to monitor the 2016 iteration of RIMPAC from a distance.

In May 2021 the U.S. Pacific Fleet tracked Kareliya lingering about 15 miles to the west of Kauai. The island is home to the Pacific Missile Range Facility Barking Sands, which is used by the Navy and the Missile Defense Agency to test-fire missiles. The Kareliya’s presence prompted American commanders to delay a planned missile test.

That incident preceded the arrival of dozens of warships from Russia’s Pacific fleet in June that conducted what Russian officials described as the largest exercise its navy has conducted in the Pacific since the end of the Cold War. Hawaii Air National Guard fighter jets scrambled several times in response to Russian bombers flying close to Hawaii’s airspace. The exercise coincided with President Joe Biden’s first meeting with Russian President Vladimir Putin since his inauguration.

After the majority of the Russian warships left Hawaii at the end of the exercise, a spy ship stayed behind to monitor maneuvers by the American aircraft carrier USS Carl Vinson.

In 2022 the military acknowledged monitoring Russian vessels off Hawaii at least twice, first in January as Biden again met with Putin, this time discussing a massive military buildup of Russian forces around Ukraine. Though Putin insisted it was only an exercise, the following month Russian forces invaded western Ukraine and expanded its war with the country. U.S. Indo-Pacific Command confirmed in May 2022 that it was again tracking a Russian military vessel around Hawaii.

The two Russian vessels in the video released Wednesday are the first the military has announced operating off Hawaii since the new year.

“The U.S. Coast Guard is currently monitoring the Russian vessel operating in the vicinity of Hawaii,” said Cmdr. Dave Milne, chief of Coast Guard external affairs, in the news release. “As part of our daily operations, we track all vessels in the Pacific area through surface and air assets and joint agency capabilities.

“The Coast Guard operates in accordance with international laws of the sea to ensure all nations can do the same without fear or contest. This is especially critical to secure freedom of movement and navigation throughout the Blue Pacific.”