The Foreign Ministry on Thursday responded to the advancement of the Magnitsky Act in the U.S. House of Representatives by issuing a warning of retaliation.
The bill, which seeks to punish Russian officials involved in the jail death of anti-corruption lawyer Sergei Magnitsky, is expected to come up for vote in the House on Friday.
Russia will get back at the United States if the bill becomes law, Foreign Ministry spokesman Alexander Lukashevich said.
"We will have to react, and it will be a tough reaction," he said, Interfax reported.
He did not specify what the government had in mind, saying only that Russia's response would depend on the final content of the "unfriendly and provocative" legislation and cover the complete range of bilateral ties.
Lukashevich also branded as "unacceptable" the linkage of the Magnitsky Act with the vote to allow permanent normal trade relations with Russia. The House Rules Committee moved Tuesday to combine the two bills into one package.
Lukashevich said the United States had no "moral grounds" to point the finger at Russia after the U.S. record of poorly treating its prisoners at Guantanamo.
William Browder, chief of Hermitage Capital, who has campaigned for passage of the Magnitsky bill, said the progress of the U.S. legislation was hugely important both in its own right and as a historic precedent.
"Twelve European countries and Canada are all looking to the U.S. before passing their own versions of the Magnitsky Act," he said. "I predict a major domino effect on this being implemented in other countries after this becomes law in the U.S."