"We're going to be present [in the Black Sea]," Mabus was quoted by the US Navy as saying. "That's the main reason we're here — to deter potential aggression; to be where we ought to be, when we ought to be there."
The Navy secretary delivered the remarks aboard US destroyer Mason in the Mediterranean Sea on Thursday.
On June 6, US Navy destroyer Porter began its 21-day routine patrol of the Black Sea in support of Operation Atlantic Resolve. The deployment drew criticism from Moscow for destabilizing the region.
Both the United States and NATO are seeking to expand their presence in the Black Sea following the 2014 reunification of Crimea with the Russian Federation, a move that NATO sees as a violation of international law.
Moscow maintains the legitimacy of the 2014 Crimea’s popular referendum to rejoin Russia. Earlier in June, Russian Foreign Ministry official Andrei Kelin said Russia would take retaliatory measures in response to the US deployment in the Black Sea.