The US Navy sent warships and aircraft to the North Atlantic to participate in the "Black Widow" exercise to respond to threats from Russian submarines.

The drill took place on September 12-13, focusing on anti-submarine warfare, the US Navy's 2nd Fleet representative said at a press conference on September 16, but did not announce the location of the exercise.

The exercise was held after US naval commanders announced increased operations of Russian submarines in the North Atlantic, "posing a new challenge" in the US as a potential "war zone".

"It's a place of fighting and competition," Vice Adm. Andrew Lewis, commander of the US Navy's 2nd Fleet, said at a press conference.

The helicopter carrier USS Wasp, the USS Arleigh Burke and USS McFaul submarines, two Virginia-class and Los Angeles-class attack submarines participated in the exercise.

The US naval commanders declined to say if they detected any Russian military activities under the sea during the exercises.

Vice Admiral Daryl Caudle, commander of the US submarine force in the US, said the Russian and Chinese armies both invest a lot in combat capabilities under the sea.