Russian President Vladimir Putin denied this week that Russia had sponsored the hackers who stole emails and documents from the computers of the Democratic National Committee and other U.S. political institutions, adding that the American public should focus on the content of the leaks rather than searching for who did it.

In a transcript of a Bloomberg News interview published Friday by the Kremlin, Putin said it was “impossible to check” on whether Russia or any other state actor was behind the theft of more than 20,000 emails that later appeared on the anti-secrecy group WikiLeaks’ website. He called the accusations against Russia by U.S. officials and politicians an attempt to “distract the public’s attention.”

“It doesn’t really matter who hacked this data from Mrs. Clinton’s campaign headquarters,” Putin said, referring to Democratic presidential nominee Hillary Clinton. “The important thing is the content was given to the public.”

The FBI is reviewing the hack, which some U.S. officials and Western cybersecurity agencies allege is the work of a Russian military intelligence service hacking team called APT 28 or Fancy Bear.

The FBI is also reviewing whether APT 28 passed the files released by WikiLeaks on the eve of the Democratic National Convention, prompting a shake-up of the committee’s leadership and concern that Moscow had launched a broad cyberespionage campaign against institutions at the heart of U.S. politics.

The FBI raised new concerns about cyberattacks against democratic institutions this week, publishing an alert about the possible hacking of state election offices after breaches in Illinois and Arizona.

Putin has not previously responded to accusations about the Democratic National Committee hack. When he was first asked about it during the interview Thursday, he chuckled.

“No, I don’t know anything about that,” Putin said in a jocular tone, raising an eyebrow as he answered the question. “You know how many hackers there are today? And they act so delicately and precisely that they can leave their mark at the necessary time and place or even not their own mark, camouflaging their activity instead as other hackers from other territories or countries. It’s an extremely difficult thing to check. It’s impossible to check.”

Without specifying those claims, Putin was answering accusations made by a number of Western cybersecurity agencies, as well as Russia’s own Kaspersky Lab, that the teams that had breached the computers of the Democratic National Committee and Democratic Congressional Campaign Committee were Russian-speaking and state-sponsored, based on clues left in their code.

“At any rate, we definitely do not do this at the state level,” Putin added.