Earlier this week, intelligence agencies reported that two Ural-4320 trucks full of armed Russian troops were observed arriving in the Black Sea port of Yalta. Photographs made by a Ukrainian civilian were posted online as the troop transports entered a Russian military facility in Yalta, on the Crimean peninsula in Ukraine.
Other activities in recent days have included the movement of armored personnel carriers observed at Russia's Black Sea Fleet headquarters in nearby Sevastopol.
U.S. officials said the purpose of the troops is not known, but speculation centers on the possibility of the troops being used as part of an advance force for a future Russian military operation.
U.S. intelligence agencies also are tracking possible covert infiltration of Russian Spetsnaz commandos. One concern is that Moscow will provoke a conflict by using the undercover commandos to attack ethnic Russians and then launch an invasion under the guise of protecting those Russians.
Some 8 million Russians reside in Ukraine, making up about 17 percent of the population.
In a sign of Moscow’s concern over losing what it regards as a strategic neighbor, President Vladimir Putin ordered Russian forces on a higher state of alert Tuesday. The mobilization includes forces some 200 miles from Russia’s southern border with Ukraine.
Asked about the Russian military activities in the Crimea, and how far the United States is prepared to go to prevent military intervention, Mr. Burns said: “All that I would stress is what I said before, and that is that the United States strongly supports the unity and the territorial integrity of Ukraine.”
“And the United States will continue to reinforce that very firm position,” he said.
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