Mark Zuckerberg apologized Wednesday for a data scandal that has engulfed the social media giant for the past several days, saying he regretted how the company handled the controversy.

"This was a major breach of trust, and I'm really sorry that this happened," the Facebook chief executive said during an interview Wednesday with CNN. "We have a basic responsibility to protect people's data and if we can't do that, then we don't deserve to have the opportunity to serve people."

The interview came after Zuckerberg finally broke his silence Wednesday over the misuse of data from more than 50 million Facebook accounts, a controversy that's consumed the social network over the past week. Facebook disclosed on Friday that information from millions of accounts on the social network was used without people's permission by Cambridge Analytica, a digital consultancy hired by the Trump presidential campaign.

But as criticism of Facebook's handling of the situation mounted, Zuckerberg and Facebook COO Sheryl Sandberg remained quiet. The lack of response from Facebook's leadership only intensified the backlash, which has lead to a #DeleteFacebook campaign.

Facebook has come under fire from lawmakers calling for Zuckerberg to answer for Facebook's actions. Prominent senators, including Democrats Amy Klobuchar and Mark Warner, have called for the CEO to testify before Congress.

"The steps Facebook has laid out to protect its users are a start but Zuckerberg still needs to come testify," Klobuchar tweeted Wednesday. She also urged the company to support new regulation around online advertising disclosures, something Zuckerberg wasn't opposed to.

"I'm not sure we shouldn't be regulated," Zuckerberg said during the CNN interview. "There are things like ad transparency regulation that I would love to see."

During the CNN interview, Zuckerberg repeated some of the steps Facebook is taking to make sure the Cambridge Analytica data exploit doesn't happen again. For starters, Zuckerberg said Facebook will "investigate" all apps that have access to large amounts of data, and restrict developers' data access even further.

"One of the most important things that I think we need to do here is make sure we tell everyone whose data was affected by one of these rogue apps," Zuckerberg said, adding that Facebook is going to build a tool that will allow users to determine whether their data was affected.

He also promised more transparency should apps stray from the company's terms in the future.

"Going froward when we identify apps that are similarly doing sketchy things, we're going to make sure that we tell people too," he said. "Looking back on this, I regret that we didn't do that at the time and I think we got that wrong."

According to Facebook, the data was originally collected by a Cambridge lecturer named Aleksandr Kogan for a personality quiz app. He collected the data legitimately, but then violated Facebook's terms by sharing the information with Cambridge Analytica.

Facebook found out about the infraction in 2015 but didn't inform the public. Instead, the company demanded that all the parties involved destroy the information. But now there are reports that not all the data was deleted.

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