The Kremlin has denied any involvement in Russia-linked Facebook advertisements that were posted on the popular social network during last year's U.S. presidential election campaign.
"We don't know who places ads on Facebook and how," President Vladimir Putin's spokesman, Dmitry Peskov, told reporters on September 22.
"We have never done it and the Russian side has never had anything to do with it," Peskov said.
Meanwhile, U.S. President Donald Trump on September 22 called reports about the Russia-linked advertisements a "hoax," saying on Twitter, "Russia hoax continues, now it's ads on Facebook."
Trump also accused U.S. media of being "totally biased and dishonest" in coverage of his Democratic rival in the election, Hillary Clinton.
Facebook has said it plans to submit to U.S. congressional investigators the contents of 3,000 political ads that it says Russia-based operatives ran on the social network in the months before and after last year's U.S. presidential election.
Chief Executive Mark Zuckerberg, who has been under pressure to do more to prevent the use of Facebook for election manipulation, said on September 21 in a live broadcast on Facebook that he supported the investigation by the U.S. Congress.
Zuckerberg presented nine steps that he said his company was taking to prevent governments from using Facebook to interfere with elections.
In one important change, Facebook, the world's largest social network, will make political ads on the social network more transparent, so that people can see which ads are being run in connection with an election, Zuckerberg said.
Colin Stretch, the company's general counsel, said in a separate blog post that Facebook did not disclose content lightly under any circumstances, but that the social network wanted to help protect the integrity of U.S. elections.
"We believe the public deserves a full accounting of what happened in the 2016 election," Stretch wrote.