The US navy has confirmed that a Russian spy ship has been stationed in international waters off Hawaii, but says its presence is not affecting military exercises.

Pacific Fleet spokesman Lt Clint Ramsden said Wednesday the Russian Navy Balzam-class auxiliary general intelligence ship had recently arrived.

“Obviously, we are aware that it is there, and we’ve taken all precautions necessary to protect our critical information,” Ramsden said. “Its presence has not affected the conduct of the exercise.”

The arrival of the ship comes as the Rim of the Pacific, or Rimpac, military drills are under way. The exercises for military forces from 26 nations will last through early August and include 45 ships, 200 aircraft and more than 25,000 people.

Troops will practice skills including clearing mines, hunting for submarines and delivering amphibious forces ashore.

Ramsden said Russia last participated in the exercises in 2012. The last time a Russian spy ship stopped by Hawaii was during the military exercises in 2004, according to Pacific Fleet.

He declined to say where the Russian ship was operating, other than that it was within the US 200 nautical mile Exclusive Economic Zone.

The United States has launched similar operations off foreign shores.

“We continue to uphold the principle of freedom of navigation and overflight in accordance with international law,” Ramsden said.