Russia warned US warships on Tuesday not to go near Crimea following their deployment to the Black Sea the day before.
There was concern in many capitals about the potential for tensions to worsen further.
Russian Deputy Foreign Minister Sergei Ryabkov was cited by Russian news agencies on Tuesday warning US warships in the area to keep their distance, saying the risk of unspecified incidents was very high.
“There is absolutely nothing for American ships to be doing near our shores, this is purely a provocative action. Provocative in the direct sense of the word: they are testing our strength, playing on our nerves. They will not succeed,” Ryabkov was cited as saying.
“We warn the United States that it will be better for them to stay far away from Crimea and our Black Sea coast. It will be for their own good.”
The US warships were expected to arrive in the area that same week, having been sent after Moscow deployed a large number of forces near its border with Ukraine and in Crimea.
NATO Secretary-General Jens Stoltenberg called on Russia on Tuesday to draw down the number of troops on Ukraine’s borders, ahead of an emergency meeting of allied foreign and defence ministers.
Ukraine’s Foreign Minister Dmytro Kuleba flew to Brussels on Tuesday for talks with Stoltenberg, a day after Kyiv accused the Kremlin of ignoring its request for talks between the two countries’ presidents over the troop build-up.
“In recent weeks Russia has moved thousands of combat-ready troops to Ukraine’s borders, the largest massing of Russian troops since the illegal annexation of Crimea in 2014,” Stoltenberg said.
“Russia must end this military build-up in and around Ukraine, stop its provocations and deescalate immediately,” he said at a news conference with Kuleba. Kuleba said Kyiv wanted a diplomatic solution.
Kyiv and Moscow have traded blame over the ongoing fighting in the eastern Donbass region which has killed 14,000 people since 2014.