Russia's undersea activity has reached levels not seen since the height of the Cold War, a NATO official said Saturday.

Rear Adm. Andrew Lennon, NATO's commander of submarine forces, told reporters that Russia's submarine activity has ticked up considerably in the past few years, with more Russian deployments spotted every year.

“Russian submarine activity is higher now in the last three years than it has been since the Cold War," Lennon said, according to the Express.

ADVERTISEMENT

“What we have observed over the past three years are more deployments annually of Russian submarines away from their local waters than we have observed in the prior decade.”

Russia's navy deteriorated after the fall of the Soviet Union in 1991. In recent years, however, the Russian government under President Vladimir Putin has made a “strong investment” toward rebuilding the country's navy, Lennon told reporters.

Lennon also noted a major increase in submarine activity around NATO undersea communication lines, according to The Washington Post.

“We are now seeing Russian underwater activity in the vicinity of undersea cables that I don’t believe we have ever seen,” Lennon said. “Russia is clearly taking an interest in NATO and NATO nations’ undersea infrastructure.”

Earlier this year, Russia's Adm. Vladimir Korolev said that Russian naval activity had reached levels only achieved during the Soviet Union.

“Last year we reached the same level as before the post-Soviet period, in terms of running hours,” Korolev said, according to the Post.

“This is more than 3,000 days at sea for the Russian submarine fleet," he added. "This is an excellent sign.”