The United States is assessing the security implications of Russia's latest deployment of S-400 air defenses to Crimea, a U.S. military official said Tuesday, adding it could give existing Russian defenses more resilience.
"It's not good. It doesn't bode well," a senior U.S. official at the U.S. military's European Command said, speaking on condition of anonymity.
"We certainly are paying attention to it and what that means, as far as the security of the Black Sea."