After a series of close encounters between Russian and NATO military aircraft over the Black Sea in recent months, the waterway is now seeing a ramping up of naval activity as well. According to a statement released by the U.S. Navy’s 6th Fleet, the Arleigh Burke-class guided-missile destroyer USS Carney has now joined its sister ship, the USS Ross in the waterway that sits on Europe’s eastern flank.

Our decision to have two ships simultaneously operate in the Black Sea is proactive, not reactive,” US Navy Vice Adm. Christopher Grady, the commander of 6th Fleet, said in a press release.

“We operate at the tempo and timing of our choosing in this strategically important region. By nature, ships are flexible, mobile forces, and the Navy is uniquely capable of providing credible and capable forces to defend our nation’s interests throughout the world.”

Saturday’s arrival of the Carney marks the first time two American warships have been in the Black Sea at the same time since Ukraine hosted a training operation in July of last year, but they won’t be alone for long. One day after the Carney’s arrival, the Kremlin announced new naval deployments to the waterway as well, with a Russian frigate, the Admiral Essen, and two patrol ships entering the Black Sea soon thereafter.