The Kremlin says US Special Counsel Robert Mueller's investigation into alleged Russian interference in the 2016 US presidential election and other related crimes will end one day, describing it as pointless.
"There's hope that it will wind up one day," Kremlin spokesman Dmitry Peskov told reporters on Tuesday when asked about the investigation.
"In Russian, it's called passing water through a sieve," he said of the US probe, using a Russian expression that means flogging a dead horse.
"That's exactly what the process looks like."
Russia has repeatedly denied allegations it interfered in the election to help Donald Trump reach the White House and has complained of what it says is an orchestrated anti-Russian campaign in the United States.
In an early morning tweet, Mr Trump accused Mr Mueller's team of "MEDDLING" in the upcoming US midterm elections.
Mr Trump has referred to Mr Mueller's team as "13 angry Democrats," although Mr Mueller is a Republican.
"The 13 Angry Democrats (plus people who worked 8 years for Obama) working on the rigged Russia Witch Hunt, will be MEDDLING with the mid-term elections, especially now that Republicans (stay tough!) are taking the lead in Polls. There was no Collusion, except by the Democrats," the US president said on Twitter.