Russia is ready to improve ties with the United States but it is up to Washington to make the first move, the Kremlin said on Monday after the conclusion of a U.S. investigation into an alleged collusion between Donald Trump and Moscow in the 2016 election.

The long-awaited final report of Special Counsel Robert Mueller's probe into Moscow's election meddling concluded that no member or associate of the campaign conspired or coordinated with Russia in its plot to boost Trump in the vote more than two years ago.

Kremlin spokesman Dmitry Peskov dismissed the report on a conference call and said Russia had never interfered and did not plan to interfere in the United States or other countries' internal affairs and elections. "... It's hard to find a black cat in a dark room, especially if there is no cat," Peskov told reporters.

Commenting on the possibility of an improvement in ties with the U.S. after the conclusion of the Mueller report, Peskov said President Vladimir Putin had repeatedly stated he was open to shoring up relations. "In this case, the ball is absolutely in their court. It was given to Trump in Helsinki," Peskov said, referring to a summit between Putin and Trump in the Finnish capital in July 2018.

While the Mueller report did not exonerate the president of obstruction of justice, Attorney General Bill Barr's letter to Congress summarizing the still-secret document cleared a dark cloud that had hung over the Trump's legitimacy since he took office in Jan. 2017. "There was no collusion with Russia. There was no obstruction. It was a complete and total exoneration," Trump said Sunday of Mueller's conclusions. "It's a shame that the country had to go through this," he added. "This was an illegal takedown that failed." Deputy press secretary Hogan Gidley said Trump was "in a really good mood" and "very happy with how it all turned out." Gidley said the president watched television, talked to staff and made calls during his flight home from Florida.

But the end of Mueller's operation did not leave Trump's White House in the clear. Democrats in Congress are already conducting some 17 investigations into the administration, spreading their net far more broadly than Mueller's relatively narrow mandate. They want the full Mueller report and are demanding the underlying evidence supporting his conclusions.

Senate Democratic Leader Chuck Schumer and House Speaker Nancy Pelosi said Barr's summary of the Mueller findings "raises as many questions as it answers." "The fact that Special Counsel Mueller's report does not exonerate the president on a charge as serious as obstruction of justice demonstrates how urgent it is that the full report and underlying documentation be made public without any further delay," they said.