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Facebook will always be free, Mark Zuckerberg says.

At a Senate hearing on Tuesday, the Facebook CEO told lawmakers a subscription-based model of Facebook wasn't on the cards. The idea users might pay for the service began circulating after Facebook's COO Sheryl Sandberg suggested members of the social network would have to pay if they didn't want to receive data-targeted ads.

"There will always be a version of Facebook that is free," Zuckerberg told senators. "It is our mission to try to help connect everyone around the world and bring the world closer together. In order to do that, we believe we need to offer a service that everyone can afford."

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The testimony comes amid the biggest scandal in Facebook's 14 years. The company has been under fire for failing to protect users' data, which was reportedly used by consultancy Cambridge Analytica for political messaging. The fallout has included concerns over Facebook's targeted advertising and a #DeleteFacebook movement.

Zuckerberg, who founded Facebook in his dorm room, added that the social network doesn't have an option for people who are willing to pay to avoid ads. He did say users can turn off ad targeting in their settings, adding that the majority of Facebook users choose to leave targeted ads on.

"People really don't like ads that aren't relevant," he told the lawmakers.

We asked 1000 US consumers if they would pay for a premium Facebook service with no advertizing: 59% said NO https://t.co/CmHinS5s5u — Carolina Milanesi (@caro_milanesi) April 10, 2018

Zuckerberg said targeted ads are Facebook's business model. Without them, Facebook would need to find another way to make money somehow.

"In order to not run ads at all, we would need some sort of business model," he told senators, referring to Sandberg's earlier comments.

Correction: Fixes quote from Zuckerberg, who used the word "service" rather than "version."