Asked whether he might get "slapped" with a "socialist" label in the general election, the self-described democratic socialist countered that Clinton had her own vulnerabilities, saying, "look at the front pages in terms of what Secretary Clinton is getting slapped with."
Sanders denied he was raising Clinton's emails as an attack.
"I'm not going to politicize that issue. I'm not attacking Hillary Clinton on that issue. I stand by what I said in the first debate," Sanders said, referring to a moment in the first Democratic debate in October when he told Clinton that Americans were "sick and tired of hearing about your damn emails."
The State Department announced Friday it would not release 22 of Clinton's emails from her tenure as secretary of state because they contained "top secret" information.
In an earlier interview on "This Week," Clinton said the emails were not marked classified at the time she handled them and called for them to be released.
"Let the public see them and let's move on," she said.