Facebook will soon release a tool that lets users see if they liked or followed any Russian propaganda during the 2016 election, the tech giant announced Wednesday.

The tool will reveal to users whether they interacted with Facebook or Instagram accounts operated by the Internet Research Agency, a St. Petersburg-based company believed to have been employed by the Kremlin to spread political messages throughout the election.

The tool will apply only to content users may have interacted with between January 2015 and August 2017. Facebook expects to roll it out by the end of the year.

“It is important that people understand how foreign actors tried to sow division and mistrust using Facebook before and after the 2016 US election,” the company said in its announcement.

Stephen Lam/Reuters Facebook CEO Mark Zuckerberg once said concerns about Facebook's role in the 2016 election were "crazy."

In September, Facebook revealed that a likely Russian-based operation spent $100,000 on thousands of ads promoting divisive political messages and that it had since deleted the accounts posting them. More than half of all eligible voters in the U.S. were exposed to that Russian propaganda between January 2015 and August 2017.

In one case, Russians masqueraded on Facebook as both a pro-Islam group and an anti-Islam group, then scheduled opposing rallies on the same day in the same area of Houston.

Facebook’s admission lent credence to U.S. intelligence agency findings that Russia meddled in the 2016 election ― a discovery that President Donald Trump has vehemently denied as federal investigations into the matter continue.

But even before revelations about the Facebook ads emerged, the tech company came under scrutiny for allowing false information from illegitimate websites to flourish on the site during the election. While Facebook founder and CEO Mark Zuckerberg dismissed concerns that this played a role in the election results as “crazy,” he later walked back those comments, saying, “This is too important an issue to be dismissive.”