Editor's Note: This article originally appeared on Business Insider.

President Donald Trump has confirmed that the United States launched a cyberattack on the Internet Research Agency (IRA), an infamous Russian troll farm, during the 2018 midterm elections.

The Washington Post first reported on the attack, which blocked the IRA's internet access, in February 2019. The administration did not comment on the report at the time, but Trump confirmed the attack in an interview with Post columnist Marc Thiessen published Friday.

Thiessen asked whether Trump had launched the attack, to which the president replied “correct.” This is the first time Trump or the White House has confirmed the attack, and it is unusual for countries to publicly talk about cyberwarfare tactics.

According to The Post's 2019 report, U.S. Cyber Command's attack started on the first day of voting for the November 2018 midterm elections, and continued for a few days while votes were tallied. “They basically took the IRA offline,” one source familiar with the matter told The Post.

“Look, we stopped it,” Trump told Thiessen. The Internet Research Agency was indicted by special counsel Robert Mueller in 2018 for conspiracy to interfere with the 2016 presidential election. Russian influence campaigns were also detected during the 2018 midterms.

Trump also claimed that President Barack Obama had remained silent on the issue of Russian disinformation campaigns ahead of the 2016 election.

“[Obama] knew before the election that Russia was playing around. Or, he was told. Whether or not it was so or not, who knows? And he said nothing. And the reason he said nothing was that he didn't want to touch it because he thought [Hillary Clinton] was winning because he read phony polls. So, he thought she was going to win. And we had the silent majority that said, 'No, we like Trump,'” Trump said.

In October 2016, the Obama administration formally accused Russia of hacking into Democratic computers to steal emails that ended up on Wikileaks. In December 2016, one month after Trump had won the election, Obama ejected 35 suspected Russian intelligence officers in retaliation.

Trump's assertion that he took a tougher stance against Russian disinformation campaigns than Obama comes the week after he commuted the prison sentence of former aide Roger Stone, a move that came just days after Facebook announced it had taken down a network of disinformation accounts after an “investigation linked this network to Roger Stone and his associates.”

Trump's attitude to Russia has come under fire from critics recently after reports emerged in late June that he was briefed on Russia offering the Taliban bounties to kill U.S. troops in Afghanistan, and chose not to retaliate.

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