Russia’s Foreign Ministry has warned of “retaliatory measures” over the entry of an American warship into the Black Sea.
The USS Porter arrived in the Black Sea port of Varna, Bulgaria, earlier this week for what the US Navy called a routine deployment.
Russian officials are reportedly unhappy over the increase in NATO activity in the region.
According to a statement from U.S. 6th Fleet, the destroyer “will conduct port visits and bilateral exercises with partner navies.”
Under the terms of the 1936 Montreux Convention, non-Black Sea countries can have no more than 9 warships in the Black Sea at one time and each ship must leave after 21 days.
The United States did not attend the Montreux conference and did not sign the agreement but historically has honoured its provisions.
The USS Porter is an Arleigh Burke-class destroyer.