Facebook is planning to strengthen its review processes for political advertisements amid criticism over the impact of secretive ads on its platform before the 2016 United States presidential elections.

The social media giant will also provide the United States Congress information on suspicious ads with alleged Russian links, used during the 2016 election campaign, Chief Executive Officer Mark Zuckerberg said on Thursday. The company called it “an extraordinary investigation”, as it “raises questions that go to the integrity of the US elections”.

Earlier this month, an internal review had found that Russia-based advertisers had spent $100,000 on 3,000 Facebook ads promoting divisive messages during and after the campaign. The company had initially refused to share details of the advertisements with the Congress.

“We are looking into foreign actors, including additional Russian groups and other former Soviet states, as well as organisations like the campaigns, to further our understanding of how they used our tools,” Zuckerberg said. “These investigations will take some time, but we will continue our thorough review.”

The company will roll out processes that bring political ads on its platform to “an even higher standard of transparency” than those on TV or other media.

Zuckerberg said Facebook will increase its investment in security, and specifically, election integrity. “In the next year, we will more than double the team working on election integrity.” The company will also expand its partnerships with election commissions around the world, he said.

The company, for the first time, will make it possible for users to see any political ads that run on Facebook, regardless of the advertiser’s target audience.

“Not only will you have to disclose which page paid for an ad, but we will also make it so you can visit an advertiser’s page and see the ads they’re currently running to any audience on Facebook,” Zuckerberg said.