The U.S. military is tracking a Russian spy ship in the Pacific Ocean near Hawaii, officials confirmed to the Star-Advertiser today.

The vessel has been in waters just outside of the Hawaii’s exclusive economic zone while commanders have monitored movements since at least Friday.

“U.S. Indo-Pacific Command is monitoring the Russian vessel operating in international waters in the vicinity of Hawaii,” INDOPACOM spokesman Maj. Rob Martins said. “As part of our normal daily operations, we closely track all vessels in the Indo-Pacific area of operations through maritime patrol aircraft, surface ships and joint capabilities. We operate in accordance with international law of the sea and in the air to ensure that all nations can do the same without fear or contest and in order to secure a free and open Indo-Pacific.”

In May, the U.S. Pacific Fleet tracked the Vladivostok-based Russian spyship the Kareliya, which was 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 officals described as the largest exercise its Navy has conducted in the Pacific since the end of the Cold War.

American jets scrambled several times in responese to Russian bombers flying close to Hawaii’s airspace. And after the majority of the warships left at the end of the exercise, a spyship stayed behind to monitor maneuvers by the American aircraft carrier USS Carl Vinson.

That exercise coincided with President Joe Biden’s first meeting with Russian President Vladamir Putin since his inauguration. A Russian spyship also lingered near Hawaii in 2016 to monitor the biennial U.S.-hosted Rim of The Pacific naval exercise.

The latest appearance of a Russian vessel this year comes as the Biden Administration works to diffuse tensions as the Russian military assembles a massive buildup on the border with Ukraine that many Ukrainians fears is the mobilization for an invasion. Russia previously invaded and annexed Ukraine’s Crimea region in 2014.

The Pentagon currently considers the Pacific its top priority of operations and considers China to be its main rival in the region, but Russia is still a major player in the region.

The Kremlin maintains military ties and arms trading deals with several countries across the Asia and maintains its own sizeable Pacific Fleet. American fishermen sailing in the Northern Pacific near Alaska have reported increasing interactions with Russian military ships and aircraft that have occasionally been described as confrontational.

Hawaii is a critical hub for U.S. military operations. INDOPACOM, which is headquartered at Camp Smith, oversees all operations across the Pacific Ocean, much of the Indian Ocean and parts of the Arctic region.

The U.S. military is increasingly recognizing connections between these regions as melting polar icecaps have begun to open new trade routes between Europe and the Pacific — along with potential undersea energy deposits that Russia and China are eager to secure.