Russia's Black Sea fleet launched naval combat exercises on Tuesday as a U.S. coastguard vessel headed to the region at a time of heightened tension between Russia and the West.
Moscow alarmed Kyiv and Western capitals in recent weeks by building up forces along the border with Ukraine, though last week it ordered a withdrawal of some troops.
Russia's Black Sea fleet said on Tuesday its Moskva cruiser would hold live-fire drills with other ships and military helicopters, Interfax news agency reported.
Hours earlier, U.S. Naval Forces in Europe said the U.S. Coast Guard vessel Hamilton, a cutter, was moving into the Black Sea to work with NATO allies and partners in the region.
The RIA news agency quoted Russia's defence ministry on Tuesday evening as saying the Hamilton had entered the Black Sea and was being tracked by the Russian fleet.
Russia said its troop build-up near the border with Ukraine was part of drills in response to what it called threatening behaviour by NATO.
Defence Minister Sergei Shoigu said on Tuesday Russia had not pulled back forces because of external pressure, and that Moscow moved troops around on its own territory as it saw fit.
"The actions of the U.S. and NATO in the European region to increase the combat readiness of troops and strengthen their forward presence is contributing to an increase in military danger," Shoigu said in comments circulated by the defence ministry.
Kyiv and the West have said it is too early to assess Russia's troop drawdown.
"We cannot guarantee 100% that Russian troops won't turn around," Ukrainian President Volodymyr Zelenskiy said on Tuesday.
A senior U.S. defence official told Reuters on Friday that Moscow's announcement of its redeployment alone was "insufficient to give us comfort." read more
Relations between Moscow and Kyiv have been dire since Russia annexed the Crimea peninsula in 2014 and backed a pro-Russian separatist insurgency in eastern Ukraine.
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