Russia has decried the uproar in the United States over Attorney General Jeff Sessions' meetings with the Russian ambassador as a replay of McCarthyism, voicing regret over the lack of any substantive dialogue with Washington.
Mr Sessions recused himself from any investigation into communications between aides to President Donald Trump and Moscow on Thursday following revelations that as senator, Mr Sessions twice spoke with Ambassador Sergey Kislyak during the 2016 election campaign and failed to say so when pressed by Congress.
Russian foreign minister Sergey Lavrov argued that contacts with officials and lawmakers are part of any ambassador's duties.
He added that the pressure on Mr Sessions "strongly resembles a witch hunt or the times of McCarthyism, which we thought were long over in the United States as a civilised country".
In the 1950s, Senator Joseph McCarthy led a hunt for purported communist infiltrators in the US government, often involving unfounded accusations.
Mr Trump blamed Democrats for the controversy in a statement on Thursday night.
He said: "They lost the election and now, they have lost their grip on reality. The real story is all of the illegal leaks of classified and other information. It is a total witch hunt!"
At a news conference, Mr Lavrov said Russia is not going to mimic the US, but added that "if we applied the same principle to Ambassador (John) Tefft's activities in Russia and his contacts, it would have made quite a funny picture".
In a sarcastic Facebook post, Russian Foreign Ministry spokeswoman Maria Zakharova said she met Mr Tefft in the ministry's lobby and warned him that he was putting himself in danger by meeting with Russian diplomats.
Asked to comment on the situation, President Vladimir Putin's spokesman Dmitry Peskov cited the US leader: "We have nothing to add to the expansive definition given by President Trump."
The Sessions case is widely seen in Moscow as part of efforts by Mr Trump's foes to block any possible rapprochement with Moscow.
Russia-US ties plummeted to their lowest level since the Cold War times during Barack Obama's presidency over the Ukrainian crisis, the war in Syria and other issues.
Mr Trump had come into office hoping to mend ties with Russia, expressing admiration for Mr Putin.
Russian lawmakers and political commentators said the allegations by US intelligence that Russia meddled in the election to help Mr Trump defeat Hillary Clinton will likely continue to weigh over his administration and prevent it from launching a meaningful dialogue with the Kremlin any time soon.
In a conference call with reporters, Mr Peskov lamented the lack of co-operation with the US on the Syrian settlement beyond the US diplomatic presence at peace talks in Kazakhstan's capital of Astana that Russia and Turkey brokered earlier this year.
"Similarly, there has been no movement forward regarding co-operation in the fight against terrorism, which causes regret," he said.
"Without waiting for these contacts to start, Russia has been consistently contributing to the fight against terrorism and scoring results," Mr Peskov said, pointing at the Russian military's role in driving the Islamic State group from the historic town of Palmyra.
Mr Trump has repeatedly promised to co-operate with Russia in fighting IS in Syria.
Mr Obama's administration had ruled out such co-operation because of Moscow's support for Syrian president Bashar Assad.
Other issues on the crowded Russian-US agenda leave little hope for any quick progress.
On Ukraine, any Trump move to soften the stance on Russia's annexation of the Crimean Peninsula and its support for a separatist insurgency in eastern Ukraine would anger his Congressional foes and put him in an even more precarious position.
If Mr Trump makes any attempt to ease the sanctions imposed on Russia by Mr Obama's administration, it could face strong resistance in Congress.
On the nuclear arms control, Mr Trump's intentions to modernise the US arsenals and his criticism of the 2010 New START nuclear arms treaty would potentially put him on a collision course with Moscow, which has signalled its desire to extend the deal after it expires in 2021.
But for now, the Kremlin is trying to show patience.
Mr Peskov sought to play down Mr Trump's proposal to raise military spending by 9%, saying that it is a domestic matter for Washington.
"It would hardly concern us until a rise in spending upsets the existing balance of strategic deterrence," he said.