Russian President Vladimir Putin ordered snap military drills in the Black Sea this week. He attended the maneuvers Friday, state-owned news agency RIA Novosti reports.
U.S. State Department spokeswoman Victoria Nuland said there was nothing particularly unsettling about the surprise drill.
"Russia has exercised in the Black Sea before," she said. "That is not particularly new."
The Black Sea maneuvers involve about 7,000 military personnel, about 250 armored vehicles and 30 warships. The state news agency said the drill is meant to test combat readiness in a region that hosts the Winter Olympic Games in 2014. It adds unannounced military drills are permissible according to international law.
Putin's announcement Thursday followed a decision by the government in Georgia to balk on a non-aggression draft over separatist republics of Abkhazia and South Ossetia.
Georgia, which borders the Black Sea, went to war with Russia in 2008 over the territories.