House Financial Services chairwoman Maxine Waters says she still needs more information about Libra — and she “absolutely” wants Facebook (FB) CEO Mark Zuckerberg to testify on Capitol Hill.

“The first thing he could tell us is why Facebook came up with this idea altogether,” said Waters in an interview with Yahoo Finance. “I think this is Facebook in its effort to broaden its influence and its power and to make more money.”

Despite the more than six hours testimony from David Marcus — Facebook’s head of Calibra — and a panel of experts, Waters told Yahoo Finance that lawmakers still don’t have a compete understanding of Libra and Facebook’s digital wallet, Calibra.

“I don’t feel as if we absolutely know what it is and how it’s going to work, but I think we did get an understanding that we’ve got to put a lot more time and attention into this to be able to understand it and make some decisions about whether it’s in the best interest of our country,” said Waters in an interview with Yahoo Finance.

Lawmakers pressed Marcus throughout the hearing about how Libra and Calibra should be regulated.

“We will not go forward until we have addressed all concerns and met the regulatory bar and oversight bar that is needed for this network to operate the right way,” said Marcus in the hearing.

Waters told Yahoo Finance she still doesn’t know which agencies should regulate Libra yet.

“That’s the problem — because we don’t know what it is. Not knowing what it is, you certainly can’t begin to talk about who should regulate it. It could be, if that it goes forward, it would be a whole new regulatory system set up. A whole new regulatory agency. I don’t know at this point. But because it is not well defined in ways that we understand, I cannot tell you who should or could be regulating something like this,” said Waters.

When asked about regulation, Marcus told lawmakers that the reason Facebook announced the project before its launch was to work with policymakers on oversight.

“We’re here and engaging with all of the regulatory bodies here in the US and around the world to ensure we have the right regulatory framework and oversight and we address all the concerns that were raised today, yesterday and that were raised by Chairman Powell and others,” said Marcus.

Marcus’ testimony did not ease Waters’ concerns.

“We’re not convinced that they understand that this cannot go forward without regulation,” said Waters.

Even if regulators figure out how to manage Libra, Facebook faces an uphill battle in gaining the trust of many lawmakers and consumers.