Russia has warned the United States that the widening of sanctions under the Magnitsky Act could hinder cooperation on Iran's nuclear program, the Syria conflict, and other major international issues.
The Foreign Ministry issued an angrily worded statement on December 30, a day after the U.S. Treasury Department imposed sanctions on four alleged rights abusers -- including two law enforcement officials linked to the case of whistle-blower Sergei Magnitsky, who died in a Moscow prison in 2009.
It came at a time when relations are severely strained over Russia's annexation of Crimea and support for separatists in a deadly conflict in eastern Ukraine.
In a statement, the Russian ministry said the new sanctions were "dictated by profoundly political motives" and vowed to retaliate.
It said that "methods of pressure will not work with Russia" and added that "the U.S. actions place in question the prospects for bilateral cooperation in resolving the situation surrounding the Iranian nuclear program, the Syrian crisis, and other acute international issues."
Permanent UN Security Council member Russia is a powerful backer of Syria's government and a partner of the United States and four other countries in talks aimed to ensure Iran does not develop nuclear weapons.
Those placed under the U.S. sanctions include Deputy Prosecutor-General Viktor Grin and Andrei Strizhov, a senior investigator with Russia's top investigative agency.
The U.S. State Department say Grin and Strizhov were added to the list after being implicated in a "cover-up" of the circumstances surrounding Magnitsky's 2009 death in prison.
Magnitsky's friends and family say he was incarcerated, tortured and denied medical treatment that could have saved his life as retribution for accusing law enforcement and tax officials of stealing $230 million from Russian coffers.
After Magnitsky died, Grin ordered a criminal investigation that led to Magnitsky's posthumous conviction on tax-fraud charges by a Russian court in 2013.
The conviction was denounced by rights groups and Western governments.
The Treasury Department said two officials from Russia's restive republic of Chechnya were also sanctioned under the law.
They are Chechen Republic Deputy Interior Minister Apti Alaudinov and Magomed Daudov, head of Chechen President Ramzan Kadyrov's administration.
The U.S. State Department said Alaudinov and Daudov were "implicated in the kidnapping, torture, and, later, framing" of former Chechen politician Ruslan Kutayev, the leader of a nongovernmental organization aiming to unite ethnic groups across the North Caucasus.
Kutayev was convicted of illegal drug possession and sentenced to four years in prison in July.
He and his lawyer have said Alaudinov and Daudov beat him after his arrest in February to obtain a forced confession.
Prominent Russian and Western rights activists describe Kutayev as a victim of political persecution.
The addition of the four individuals to the U.S. blacklist brings the total number of Russians sanctioned under the Magnitsky Act to 34.
The law also allows for a classified blacklist of sanctioned Russian citizens.