The Viktor Leonov SSV-175 spy ship seen at a Havana port in 2014. REUTERS/Stringer

A Russian spy ship spotted about 70 miles off the coast of Delaware on Tuesday has begun "loitering" 30 miles from a US Navy submarine base in Connecticut, according to Fox News' Lucas Tomlinson.

The intelligence-gathering ship, the Viktor Leonov, can intercept intelligence from nearby transmitters with a variety of sensors, and it can also measure Navy sonar emissions.

"We are aware of the vessel's presence," Lt. Col. Valerie Henderson, a Defense Department spokeswoman, told Business Insider on Tuesday.

"It has not entered US territorial waters," she added. "We respect freedom of navigation exercised by all nations beyond the territorial sea of a coastal state consistent with international law."

US Navy spy ships conduct similar missions near Russia and in international waters around the globe, but usually in waters near US allies.

The timing of this incident coincides with a flurry of news coming out of Washington about Michael Flynn's resignation as national security adviser for having inappropriate conversations with Russia's ambassador to the US.

Additionally, news broke Tuesday that Russia had developed and deployed nuclear-capable cruise missiles that violate the Intermediate-Range Nuclear Forces Treaty in a move that is sure to draw a response from the US.