Russia said the US move to propose new sanctions on Moscow is taking already battered ties between the two nations into uncharted waters.
Russia warned on Wednesday that new US sanctions against Moscow would take already battered ties into uncharted waters.
Moscow said it was close to taking retaliatory measures of its own.
Russia was responding after the US House of Representatives overwhelmingly voted to impose new sanctions on Moscow and to force President Donald Trump to obtain lawmakers' permission before easing any sanctions on Russia.
"This is already having an extremely negative impact on the process of normalising our relations," Russian Deputy Foreign Minister Sergei Ryabkov said.
US-Russia relations were entering "uncharted territory in a political and diplomatic sense," he added.
TRT World 's Daria Bondarchuk reports from Moscow on the latest developments.
Konstantin Kosachyov, who heads the foreign relations committee in Russia's upper house of parliament, called on Moscow to devise a "painful" response to the US move.
Russia has repeatedly warned the US it will retaliate against what it sees as hostile moves, and Ryabkov made clear Moscow was growing tired of showing restraint.
The Russian Foreign Ministry said earlier this month that too many American spies operated in Russia under diplomatic cover and that it might expel some of them to retaliate over Washington's expulsion of 35 Russian diplomats last year.
That warning reflected rising frustration in Moscow over the Trump administration's refusal to hand back two Russian diplomatic compounds, which were seized at the same time as the diplomats were sent home.
Many Russian politicians believe Trump's political opponents and Congress have successfully reduced the US president's room for manoeuvre on Russia to almost nil.
Germany opposes US move
Germany warned it would be unacceptable for the US to use possible sanctions against Russia as a tool of industrial policy and called for close coordination of proposed sanctions between Europe and Washington.
A German foreign ministry spokesman said Berlin wanted to work with the US on the sanctions.
He, however, added that the proposed sanctions would not necessarily be adopted, and that he "could not accept" the practice of carrying out industrial policy under the guise of sanctions.