Sen. Bernie Sanders (I-Vt.) doesn't know who he'd pick to be his running mate if he wins the Democratic presidential nomination, but he definitely knows who it won't be.

In an interview with The New York Times editorial board published Monday, Sanders was reluctant to declare who he'd pick as vice president. Considering, the Iowa caucus hasn't even happened yet, Sanders called choosing someone to round out his hypothetical ticket "a little bit premature," but he did say the person "will not be an old white guy."

The 78-year-old Sanders said he believes in diversity and promised his cabinet "will look like what America looks like," adding that "the country is long overdue for the kind of diversity that we're going to bring to the White House."

That's all he was willing to reveal for now, acknowledging his campaign hasn't considered any specific names at this point.

He did rule out one person though — former Vice President Joe Biden. The senator said Biden's eight years as President Obama's right-hand man was "probably enough." Read the full interview at The New York Times. Tim O'Donnell