The Obama administration has sanctioned top allies of Russian President Vladimir Putin,  including a senior federal investigator, and the alleged assassins of Alexander Litvinenko, a former Russian spy.

The men accused of poisoning Litvinenko in London in 2006, Andrei Lugovoi and Dmitri Kovtun, were among five Russians sanctioned under the Magnitsky Act, a United States law that allows punitive measures against Russians.

The punishment freezes all their US assets and bars them from travelling to the country.

The State Department did not detail what the new targets are accused of, but the move comes at a time of increased diplomatic tension with Moscow.

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“Each of the most recently added names was considered after extensive research,” State Department spokesman John Kirby said.

Kirby said the individuals had “roles in the repressive machinery of Russia’s law enforcement systems, as well as individuals involved in notorious human rights violations”.

Federal prosecutor Alexander Bastrykin is one of Putin’s most powerful allies and is head of an investigative agency that had led alleged crackdowns on domestic dissidents.

Lugovoi and Kovtun were accused of poisoning Litvinenko, a former Russian agent turned freelance investigator who had collaborated with British intelligence.

Litvinenko is believed to have ingested polonium-210 , which is produced in nuclear reactors, while drinking tea with Kovtun and Lugovoi.

President Barack Obama’s outgoing administration has already accused the Kremlin of cyber espionage to influence the US elections. It also  expelled 35 Russian diplomats .

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A senior official told the AFP news agency that Obama’s final update to the Magnitsky Act does not include Putin himself, because the US does not want a complete breakdown in ties.

“We need to preserve the possibility of working with Russia in areas in which it is in the US national interest,” the official told AFP, on condition of anonymity.

“Our goal in imposing sanctions is to change behaviour,” he said. “We have taken steps to make clear that interference in US democratic processes will not go unanswered.”

The Magnitsky Act was originally passed to enable US officials to impose sanctions on Russians implicated in the 2009 prison death of Russian tax fraud whistleblower Sergei Magnitsky.The total list of targets now includes 44 names.


U.S. Blacklists 5 Russians, a Close Putin Aide Among Them

WASHINGTON — The Obama administration has blacklisted five Russians, including the government’s chief public investigator, who is a close aide to President Vladimir V. Putin, for human rights abuses, laying down a marker for President-elect Donald J. Trump less than two weeks before he takes office with a vow to thaw relations with Russia.

The sanctions, announced Monday by the Treasury Department, are not related to allegations of Russian hacking during the presidential election, according to a senior administration official. But they carry symbolic weight at a charged moment, as likely the last visible act the United States will take against Russia before power is transferred in Washington.

The biggest name added to the list is that of Aleksandr I. Bastrykin, who reports directly to Mr. Putin and has carried out political investigations on his behalf. Mr. Bastrykin, officials said, was complicit in the case of Sergei L. Magnitsky, a lawyer who died in detention in murky circumstances in November 2009 and for whom the Magnitsky Act was named.