The US Treasury hit 15 members of Russia's GRU military intelligence agency with sanctions Wednesday over their alleged roles in interference in the 2016 presidential election and hacking the World Anti-Doping Agency.

Also sanctioned were two GRU agents who allegedly attempted to assassinate Russian defector Sergei Skripal in Britain, and two individuals and three companies tied to the Russian troll farm accused of trying to manipulate US public opinion.

Separately, the Treasury said it would end sanctions on Russian aluminum giant Rusal and two related companies after blacklisted billionaire Oleg Deripaska took action to sharply cut his stake in them.

The sanctions ban Americans and companies with US arms -- like many global banks -- from doing business with those on the US blacklist.

The sanctions also freeze any of the targets' assets in US jurisdictions.

"The United States will continue to work with international allies and partners to take collective action to deter and defend against sustained malign activity by Russia, its proxies, and intelligence agencies," said Treasury Secretary Steven Mnuchin.

Already indicted

Most of the names on the new sanctions list were GRU officers already covered by separate US blacklists and indictments.

Four were indicted in October over the cyber attacks on the global chemical weapons watchdog, the OPCW and on WADA between 2016 and 2018.

Nine were part of a group indicted by Special Counsel Robert Mueller, the head of the investigation into Russian meddling in the 2016 election, in July.

The new sanctions came two days after two extensive reports were released detailing concerted Russian attempts to stoke US political conflict over social media by the St Petersburg-based Internet Research Agency, an operation US intelligence says was dubbed Project Lakhta.

The IRA is controlled by the Concord Group of Yevgeniy Prigozhin, a close ally of Russian President Vladimir Putin

Wednesday's sanctions blacklist added Concord's accountant for Project Lakhta -- also already indicted in the United States -- and three companies the Treasury said the Concord group used to mask its operations.

Oligarch Deripaska pressured

The delisting of Rusal and the two other companies, En+ Group and JSC EuroSibEnergo, came as they sought to avoid being locked out of global markets due to their close association with Deripaska.

Derispaska is known to have friendly ties with Putin and had business ties with president Donald Trump's former campaign chairman Paul Manafort, who has been indicted and convicted by the Mueller investigation.

"Russian oligarch Oleg Deripaska will remain sanctioned, and his property will remain blocked," the Treasury said in a statement.

Deripaska was one of several oligarchs sanctioned in April 2018 in retaliation for what the Trump administration called "the Russian government's ongoing and increasingly brazen pattern of malign activity across the world," citing its interference in Syria and its seizure of Crimea.

Also in Wednesday's sanctions, Victor Boyarkin, a former GRU officer, was blacklisted over his work with Deripaska.

"Deripaska and Boyarkin were involved in providing Russian financial support to a Montenegrin political party ahead of Montenegro’s 2016 elections," the Treasury said.