Zuckerberg also said he regrets dismissing claims that Facebook helped influence the election as a "pretty crazy idea".
Zuckerberg had dismissed the idea that fake news on Facebook helped influence election as a "pretty crazy idea".
The announcement comes nearly 10 months after Election Day in November last year.
"I care deeply about the democratic process and protecting its integrity," CEO Mark Zuckerberg said.
Clinton's vanity shines through in her new book, What Happened, which fails to answer her critics' questions.
Democratic Senator Mark Warner said he was "disappointed that Facebook didn't come forward with this information".
The social media site said the ads were consistent with what they referred to as 'information operations'.
Founder Julian Assange apparently declined to publish and "gave excuse after excuse".
Clinton warned about Trump and the emergence of the alt-right in America.
Robert Mueller's investigation into Russian interference in the US election is ramping up.
Facebook traced the fake personas to tools used by Russia's GRU military intelligence.
The report comes amid the ongoing federal investigation into Russian interference in the 2016 US elections.
The US president made his comments ahead of his first meeting with the Russian leader at the G20 summit.
Major voting flaw found by security researcher left nearly 7 million records open to hackers.
Jim Messina apparently predicted that Theresa May was set for a majority of 92 seats.
Multiple reports have suggested Comey mistated facts about Huma Abedin forwarding emails.
Comey's infamous letter is often pointed to as a reason Hillary Clinton lost to Donald Trump.
"It's very hard to say who did the hacking," President Donald Trump said.
Facebook was heavily criticised during the election season over the rampant spread of fake news on its site.
Putin had allegedly asked the Russian Institute for Strategic Studies to draw a plan that would support Trump.
President was a vocal supporter of Knox during Meredith Kercher murder trial in Italy.
Social media users were quick to point out the irony saying Conway's tweet 'did not age well'.