Democratic presidential candidate Bernie Sanders says his campaign advertisement contrasting his approach to Wall Street reform with that of Hillary Clinton is "not a negative ad."

"It portrays a fact of life," Sanders said of the ad during an interview taped for Sunday's "Face the Nation." "There are parts of the Democratic party that have taken a whole lot of money from Wall Street, pushed the deregulation of Wall Street, opposed the reestablishment of Glass-Steagall and breaking up the large banks. It is a simple and truthful statement."

The ad never mentions Clinton by name, but it clearly targets her position on financial reform, highlighting one "Democratic [vision] for regulating Wall Street" that "says it's okay to take millions from big banks and then tell them what to do." When "Face the Nation" moderator John Dickerson asked Sanders whether the ad attacks Clinton's character - something he pledged not to do - the senator suggested that's not the case.

"No. What I am saying is that there is a division within the Democratic party that has gone on for many, many years," Sanders explained. "And I'll let people determine whose side she is on and whose side I am on. I have led the effort when I was in the House against the deregulation of Wall Street. I have stood up to Wall Street, and I believe that when you have a handful of financial institutions with so much economic and political power, they have got to be broken up."

Dickerson asked Sanders whether he's arguing that Clinton's Wall Street donations would compromise her ability to regulate the industry as president.

"I think that people, in selecting a president of the United States, have got to take a hard look at their entire careers and where they get their funding from," Sanders replied. "There is no great secret: Hillary Clinton has received a lot of money from Wall Street and other very powerful special interests. I receive virtually all of my money from small, individual contributors."

"Let's not be naive," he added. "There is a reason why powerful special interests make contributions to candidates. I am very proud that we do not have a super PAC. That we have received more individual contributions than any candidate in the history of this country at this point in the campaign, averaging 27 bucks. Do I think that is an important consideration for voters? Yeah, I do."

Clinton, for her part, has suggested that her plan is actually a tougher, smarter approach to regulating Wall Street than the one outlined by Sanders. She's argued that his plan would not ensure adequate oversight of hedge funds, insurance companies, and other non-bank entities that play a significant role in financial markets.

To see more of our interview with Sanders, make sure you tune into this Sunday's broadcast. Check your local listings for airtimes.