The Trump government has lifted sanctions on three companies associated with Russian oligarch Oleg Deripaska, an ally of President Vladimir Putin.
The boundaries of the aluminum giant US Rusal, En + Group and JSC EuroSibEnergo were lifted after Mr Deripaska relinquished control.
The oligarch has been linked to the investigation of Russia's alleged interference in the US election, and the Democrats wanted the sanctions to continue.
But the Ministry of Finance said the limits of the oligarchs themselves remained in force.
The companies were blacklisted last April when the Trump government targeted individuals and companies profiting from a Russian state that had "vicious activities" around the world
These included Russia's alleged interference in the US US presidential elections 201
But earlier this month, Republicans in the US Senate blocked sanctions against Rusal, the world's second largest aluminum company, and other Deripaska-affiliated companies.
She and the Trump administration argued that the cuts could affect the global aluminum industry. They also said that Mr. Deripaska had reduced his stake in the companies so that he no longer controlled them, a sign that the sanctions were working.
Kim Gittleson, Business Reporter
The Trump administration has been pressured by business groups to lift sanctions on these three companies. The announcement of sanctions in April resulted in a short price increase in global aluminum prices, as Rusal is one of the largest suppliers in the world.
But when the Treasury signaled its intentions in December, US politicians scream. They demanded that the Trump government wait until a special investigation into Russia's involvement in the 2016 US presidential election was completed.
In early January, 136 members of President Trump's Republican Party voted with House democrats to protest the lifting of sanctions. Although it was a largely symbolic vote – a similar move the day before had not received the required 60 votes in the Senate – the large number of party rebellions was notable.
While the Ministry of Finance has insisted that the three companies do so, it agreed to the strict new reporting requirements and stated that the center-point of the conflict, Russian oligarch Oleg Deripaska, had significantly reduced his ownership. The lifting of sanctions less than a year after their imposition will certainly raise questions about Trump's commitment to punish Russia for interfering in the 2016 elections.
In a statement issued on Sunday, the US Treasury Department said that the three companies had also agreed "comprehensive ongoing audits" to ensure that they had no connections with the Russian billionaire.
And Power Company EN +, in which Mr. Deripaska held a majority stake, welcomed the message from Washington. Shares of the London-listed company collapsed when the sanctions were announced last April.
The company's chairman, Lord Barker of Battle, said: "This is the first time that independent directors of a London-listed Russian company, with the strong backing of minority shareholders, have successfully removed control of a majority shareholder as a direct response to the US Sanctions policy. "
However, policymakers have said it is inappropriate to relax sanctions on oligarchs, while Special Prosecutor Robert Mueller is investigating whether Mr Trump's presidential campaign is in cooperation with Moscow.
Deripaska, 51, was a recurring person in the investigation and has ties to former election chairman of President Donald Trump, Paul Manafort, who pleaded guilty in September 2018 that he had tried to manipulate the United States and to conspire.
Last Belarussian model Nastya Rybka was briefly detained by the Russian police and claims to have demonstrated Russia's involvement in the election campaign won by Mr Deripaska.
Deripaska has denied the allegations and successfully sued them.
President Trump denies the agreement, and Moscow denies the attempt to influence the US election on behalf of Trump, although the US intelligence agencies had noted this.