"If she (Warren) gets elected president, then I would bet that we will have a legal challenge and I would bet that we will win the legal challenge. And does that still suck for us? Yeah. I mean, I don't want to have a major lawsuit against our own government," he said, according to the leaked audio.
Warren, who in March called for breaking up Amazon.com Inc , Facebook Inc and Alphabet Inc, quickly issued a retort on Twitter.
"What would really 'suck' is if we don't fix a corrupt system that lets giant companies like Facebook engage in illegal anticompetitive practices, stomp on consumer privacy rights," Warren tweeted.
In the audio, Zuckerberg said breaking up big tech companies would make election interference "more likely because now the companies can't coordinate and work together."
Zuckerberg also drew laughter by saying Facebook's investment on safety is bigger than Twitter's entire revenue.
Zuckerberg issued a statement on his Facebook page, linking to The Verge's transcript, though he said it was meant to be internal.
"You can check it out if you're interested in seeing an unfiltered version of what I'm thinking and telling employees" he wrote in the post.