The United States suspends bilateral trade talks with Russia . In one ominous incident , a Ukrainian Defense Ministry spokesman said the commander of Russia 's Black Sea fleet boarded a blocked Ukrainian warship and issued a threat . Ukraine envoy : Russian has sent 16,000 troops into Crimea . Russia says Yanukovych asked them to send troops . Comment:
The United States suspends bilateral trade talks with Russia . Ukraine envoy : Russian has sent 16,000 troops into Crimea . Russia says Yanukovych asked them to send troops . Comment: