"We are not going to tolerate blackmail and reserve the right to take measures in response," the Russian Foreign Ministry said in a statement here.
The ministry said the sanctions, imposed by the US Treasury Department Wednesday and targeting individuals and major Russian firms in the financial, energy and arms sectors, are a "primitive attempt to take revenge for the fact that events in Ukraine are not unfolding in line with Washington's scenario", Xinhua reported.
Russia was also "disappointed" that the EU had decided to follow suit and had "yielded to the US blackmail".
The statement said the EU's move was "fraught with problems not only for Russia, but for the EU member states themselves, many of which are experiencing serious economic problems".
Russian President Vladimir Putin, who is currently in Brazil, said the sanctions would have a "boomerang effect" and push US-Russian relations to a dead end, but Moscow was still open for dialogue.