The U.S. Treasury has imposed sanctions on several Russian nationals and companies as Washington warned it was ready to tighten the economic screws further on Moscow if it did not change its ways.
"Though Russia's malign activities continue, we believe its adventurism undoubtedly has been checked by the knowledge that we can bring much more economic pain to bear using our powerful range of authorities," acting Deputy Treasury Secretary Sigal Mandelker told the Senate Banking Committee on August 21.
"We will not hesitate to do so if its conduct does not demonstrably and significantly change," Mandelker added.
U.S. President Donald Trump has spoken often of improving ties with the Kremlin, but even a face-to-face meeting in Helsinki last month with Russian President Vladimir Putin has failed to turn relations around.
U.S. lawmakers have called for more action to punish Russia for its 2014 annexation of Crimea, involvement in conflicts in Syria and Ukraine, and what U.S. intelligence agencies have described as cyberattacks seeking to influence U.S. elections.
Putin has repeatedly rejected accusations of attempting to influence U.S. elections, including the 2016 presidential vote that brought a shock victory to Trump.
Mandelker's comments came after the Treasury announced sanctions on two Russian nationals, as well as a Russian company and a Slovak firm, for attempting to evade U.S. sanctions that target malicious cyber-related activities.
Russian Deputy Foreign Minister Sergei Ryabkov called the new sanctions groundless and promised a response from Moscow.
The Treasury said St. Petersburg-based Vela-Marine Ltd and Slovakia-based Lacno S.R.O., as well as the two individuals, Marina Igorevna Tsareva and Anton Aleksandrovich Nagibin, were linked to a previously sanctioned entity -- Divetechnoservices.
"The Treasury Department is disrupting Russian efforts to circumvent our sanctions," Treasury Secretary Steven Mnuchin said in the statement.
"Today's action against these deceptive actors is critical to ensure that the public is aware of the tactics undertaken by designated parties and that these actors remain blocked from the U.S. financial system," Mnuchin added.
Divetechnoservice, a company that builds one-man submersibles that may have been used to tap underwater communications cables, was sanctioned in June for procuring underwater equipment and diving systems for Russian government agencies, including Russia's FSB intelligence agency.
In addition, the Treasury announced sanctions on two Russian shipping companies and six vessels it said were involved in the transfer of refined petroleum products to North Korean vessels in violation of UN restrictions.