The Russian Navy is edging closer to Hawaii with a big exercise 300 to 500 miles west of the Aloha State — prompting the Air Force to scramble three missile-armed F-22 fighters on Sunday, CBS News reported Tuesday.

Russian officials said it is the largest exercise in the Pacific since the end of the Cold War and involves surface ships, anti-submarine aircraft and long-range bombers, the news outlet said.

Citing U.S. defense officials, CBS said the United States scrambled the F-22s from Hawaii on Sunday in response to Russian bomber flights, but the aircraft did not enter the Air Defense Identification Zone and were not intercepted.

“At the same time, officials said a U.S, carrier strike group headed by the USS (Carl) Vinson is operating about 200 miles east of Hawaii, conducting a strike group certification exercise,” CBS said. “The exercise had been planned but was moved closer to Hawaii in response to the Russian exercise.”

CBS noted the Russian exercise comes ahead of a meeting between President Joe Biden and Russian President Vladimir Putin.

“U.S. Indo-Pacific Command is monitoring the Russian vessels operating in international waters in the Western Pacific,” Navy Capt. Mike Kafka, a spokesman for the Oahu-based command, said in an email. “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.”

He added that, “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. As Russia operates within the region, it is expected to do so in accordance with international law.”

Officials on Monday would not disclose why the three missile-armed Hawaii Air National Guard F-22 fighters were scrambled Sunday afternoon for an “irregular air patrol” requested by the Federal Aviation Administration.

“The 154th Fighter Wing launched two F-22 Raptors from Joint Base Pearl Harbor-Hickam at approximately 4 p.m.,” Pacific Air Forces said in an email. “A third was launched at approximately 5 p.m.”

The Hickam-based Air Force command added that the FAA requested that U.S. Indo-Pacific Command “conduct an irregular air patrol and the situation resolved, prompting the fighters and a KC-135 Stratotanker (a refueling plane) to return to base. We cannot discuss further specifics of the situation.”

The FAA was equally cryptic: “We have a close working relationship with the military,” spokesman Ian Gregor said in an email in response to a query asking why the military jets were requested.

The Air Force has F-22s, pilots, maintainers and weapons crews on call 24 hours a day at Hickam to respond to air threats to the Hawaiian islands as part of an air defense alert mission.

Meanwhile, a U.S. missile defense test was delayed off Kauai late last month due to the presence of a Russian surveillance ship, an official previously said. The test eventually was carried out with a salvo of SM-6 ship-fired missiles failing to intercept a medium-range ballistic missile target.

The Missile Defense Agency, in cooperation with the U.S. Navy, said it conducted what it called Flight Test Aegis Weapon System 31.

“The objective of the test was to demonstrate the capability of ballistic missile defense (BMD)-configured Aegis ship to detect, track, engage and intercept a medium-range ballistic missile target with a salvo of two Standard Missile-6 Dual II (BMD-initialized) missiles. However, an intercept was not achieved,” the agency said in a news release.

A Russian spy ship loitering in international waters off Kauai for several days had delayed the missile test, an official said.

U.S. Pacific Fleet at Pearl Harbor said in a statement at the time that it was “aware of the Russian vessel operating in international waters in the vicinity of Hawaii, and will continue to track it through the duration of its time here. Through maritime patrol aircraft, surface ships and joint capabilities, we can closely monitor all vessels in the Indo-Pacific area of operations.”

An official said the test was delayed because the United States did not want the Russian vessel to “collect on” the effort.

U.S. Naval Institute News, which was the first to report the presence of the ship, said it was the Russian Navy Vishnya-class auxiliary general intelligence, or AGI, ship Kareliya (SSV-535).

The Vladivostok-based ship is one of seven AGIs specializing in signals intelligence, USNI News said.