Russia said on Thursday it was introducing its own sanctions against US officials, minutes after US President Barack Obama announced new sanctions against Russian officials over the Crimea crisis.
"There should be no doubt: each hostile attack will be met in an adequate manner," the Russian foreign ministry said, adding that nine Obama aides and senators would not be able to enter Russia.
Moscow's blacklist includes Senate Majority Leader Harry Reid, House Speaker John Boehner and Robert Menendez, chairman of the Senate Foreign Relations Committee, as well as senators John McCain, Mary Landrieu and Daniel Coats.
Also on the list are Obama aides Caroline Atkinson, Daniel Pfeiffer and Benjamin Rhodes.
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The foreign ministry said the travel bans had been introduced in response to a US move Monday to slap financial sanctions on seven top Russian government officials and lawmakers.
"We have repeatedly warned that the use of sanctioning instruments is a two-way street and will hit the United States as a boomerang," the ministry said.
Moscow said Washington did not want to acknowledge that residents of the Russian-speaking peninsula of Crimea had overwhelmingly voted to split from Ukraine and join Russia and that the move was in line with international law.
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"One may not like that decision but we are talking about a reality which needs to be taken into account," the foreign ministry said.
Obama meanwhile announced fresh sanctions on more Russian officials and threatened to target the broader Russian economy if Moscow escalates its actions against Ukraine.
There was no immediate reaction to the new US measures and Russian President Vladimir Putin's spokesman Dmitry Peskov was not immediately available for comment.
For full coverage on the Crimean crisis, click here.