Mark Zuckerberg appeared on CNN Wednesday night to talk about how Cambridge Analytica, a data mining company, got access to profiles of 50 million Facebook users. Zuckerberg, who wrote a lengthy post on his own site earlier in the day, admitted that the company he founded in his dorm room made "a mistake."

"We need to make sure we never make that mistake ever again," Zuckerberg told CNN's Laurie Segall.

Zuckerberg, during the pre-recorded interview, says that Facebook knew in 2015 that Cambridge Analytica had bought data that an app developer collected through a Facebook survey from millions of users. After discovering this information, Zuckerberg says Facebook went to Cambridge Analytica — as well as anyone else who had received that data — to certify that they had destroyed the information.

Facebook received that certification — which Zuckerberg says he and his company trusted.

"This was clearly a mistake," he told CNN.

Facebook is being queried about its role in the 2016 U.S. Presidential election — and being eyed about how the network may be used to sway people in the mid-term elections coming up in the U.S. this November. Does Zuckerberg believe that Facebook impacted the results in 2016?

"It's really hard for me to have full assessment of that," he says. "There are so many forces at play."

But when pressed on whether he believes people are using the network today to influence upcoming elections, Zuckerberg says Facebook is deploying new A.I. to combat concerns, such as fake accounts.

But, he added, he does believe there is a "version 2," out there today, with people trying to repeat the division they were able to create on Facebook in 2016. "I'm sure someone's trying," he says.

Regulators and lawmakers in both the U.S. and the UK are eager to hear from Zuckerberg directly. But as to whether he will make an appearance on Capital Hill, Facebook's CEO played a bit coy.

"We try to send the person from Facebook who will have the most knowledge," he says. "If that is me, I'm happy to go."