Russia imposed retaliatory sanctions on nine United States officials and lawmakers on Thursday as tension over Moscow's annexation of Crimea mounted, warning the West it would hit back over "every hostile thrust".
President Vladimir Putin's spokesman said the US sanctions imposed this week were unacceptable and that the Kremlin would act on the principle of reciprocity.
Three White House officials and five US senators – Harry Reid, Robert Menendez, John McCain, Mary Landrieu and Dan Coats – were among the Americans barred from Russia, the Russian Foreign Ministry said.
US House of Representatives Speaker John Boehner was also on the list.
"We have repeatedly warned that sanctions are a double-edged instrument and would hit the United States like a boomerang," the Russian Foreign Ministry said. "There must be no doubt: We will respond adequately to every hostile thrust."
Moscow's action followed US sanctions on Russian, Ukrainian and Crimean individuals announced by President Barack Obama on Monday and again on Thursday.
The latest US sanctions, which also involved a bank, targeted several individuals close to Putin in retaliation for his military seizure of Ukraine's Crimea region. Any assets they have in the United States will be frozen and they will also be barred from US travel.
"The appearance of some of the names on the list causes nothing but extreme perplexity," Putin's spokesman Dmitry Peskov said. "But no matter what the names are, the practice of (issuing sanctions) lists is unacceptable for us."
The White House officials cited by Moscow were senior Obama adviser Dan Pfeiffer and deputy national security advisers Ben Rhodes and Caroline Atkinson.
Lawmakers in Washington were quick to welcome their new designation.
"If standing up for the Ukrainian people, their freedom, their hard earned democracy, and sovereignty means I'm sanctioned by Putin, so be it," said Menendez, a New Jersey Democrat who is chairman of the Senate Foreign Relations Committee.
McCain threw in a bit of sarcasm.
"I guess this means my spring break in Siberia is off, my Gazprom stock is lost, and my secret bank account in Moscow is frozen," said the Arizona Republican, who travelled to Kiev in December and addressed huge crowds of protesters against what was then Ukraine's Moscow-backed government.
Peskov said the Kremlin was studying the latest US sanctions list and Swiss-based oil trading firm Gunvor said it was assessing the impact of the inclusion of the company's Russian shareholder Gennady Timchenko.
A Gunvor statement said Putin had no ownership, beneficial or otherwise, of the firm, and any understanding otherwise was "fundamentally misinformed and outrageous".
Russian Railways, the country's railway monopoly, said the decision to put its president Vladimir Yakunin on the US list was unjustified.
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