Troops in unmarked uniforms atop military vehicle bearing Russian number plate and emblem, Sevastopol, Ukraine
WASHINGTON -- The list of possible sanctions against Russia for sending troops in Ukraine's Crimea region continues to grow.
In Washington, the Pentagon says it will cut contacts with the Russian military.
A senior official says the U.S. will not go forward with some trade talks with Moscow.
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In Brussels, European Union leaders have called a special summit for Thursday, where they are expected to freeze visa liberalization and economic cooperation talks with Russia.
Meanwhile, Russian President Vladimir Putin reportedly has ordered troops participating in military exercises in western Russia near the Ukraine border to return to their permanent bases.
That's what a Putin spokesman tells the Interfax news agency. The order comes almost a week after Russia began massive exercises involving most military units in western Russia, stoking fears that the Kremlin might use the troops to seize territory in pro-Russian areas of eastern Ukraine.
Russian troops said to be 16,000 strong tightened their stranglehold on Ukraine's Crimean Peninsula over the weekend, openly defying calls by the U.S. and European Union to withdraw from the region.