The controversy has not abated despite Facebook initiatives including a new tool that shows all political advertising that is running on the network and new fact-checking efforts to inform users about obvious falsehoods.
But the company reiterated on Tuesday that it will not take down postings simply because they are false. Chief Executive Mark Zuckerberg last week drew fire for citing Holocaust denials as an example of false statements that would not be removed if they were sincerely voiced.
Tuesday's briefing, which included Nathaniel Gleicher, head of cybersecurity policy, and Tessa Lyons, manager of Facebook's core "news feed," came just before the publication of an internal staff message from Facebook's outgoing chief security officer that was sharply critical of many company practices.