The US State Department said on Wednesday it would impose fresh sanctions by the month's end after determining that Moscow had used a nerve agent against a former Russian double agent, Sergei Skripal, and his daughter, Yulia, in Britain.
Sergei Skripal, 66, and his daughter Yulia were found slumped unconscious on a public bench in the English city of Salisbury on March 4.
In late March, Trump ordered 60 more Russian diplomats expelled from the U.S. as part of a global response to the attack - a response that included similar expulsions of diplomats from other nations checking Russia.
The poisoning case gained further traction in June when a British couple with no apparent ties to Russian Federation died from an accidental encounter with a similar nerve agent in the nearby British town of Amesbury.
Following a 15-day congressional notification period, the sanctions will take effect on or around August 22, according to a statement from the State Department.
In response to the United States announcement, the Russian Embassy in the USA issued a statement referring to "far-fetched accusations" and saying Russian officials had yet to hear any facts or evidence and that the U.S. had refused to answer questions.
Foreign ministry spokeswoman Maria Zakharova said this afternoon that Moscow was starting to work on measures following Washington's decision to impose sanctions, which she claimed were using the Salisbury attacks in March as a pretext.
A spokesman for Russian President Vladimir Putin called the measures "unfriendly" and "unlawful".
Nerve agent attack: What is Novichok? One of them died.
He went on to say the sanctions "contravene global law".
Wednesday's announcement comes less than a month after a summit between Trump and Russian President Vladimir Putin in Helsinki that has sparked concern among both Democrats and Republicans over the president's reluctance to hold the Kremlin to account for interfering in US elections.
Trump has not shied away from condemning the Skripal attack, but critics have questioned why it has taken the US government so long to impose the new sanctions in response.
"We are being threatened with further escalation of sanctions pressure", she said.
Elaborating in a briefing today, a State Department official said the most significant sanction is "the imposition of a presumption of denial for all national security sensitive goods or technologies that are controlled by the Department of Commerce pursuant to the Export Administration Regulations".
The announcement in Washington was likely to intensify troubles for the ruble, which took a hit Wednesday along with the stock market over rumors of separate new tough United States sanctions over election meddling.
Paul said the letter "emphasized the importance of further engagement in various areas including countering terrorism, enhancing legislative dialogue and resuming cultural exchanges". His administration has sanctioned a number of Russian officials and oligarchs for human rights abuses and election meddling.