US Sen. Bernie Sanders at the US Capitol in Washington, DC, June 9, 2016. Reuters/Jonathan Ernst If Sen. Bernie Sanders controlled which candidates qualified for the official presidential debates, some of this year's third-party candidates would likely be onstage.

In an interview on "Meet the Press" on Sunday, the Vermont senator would not weigh in on whether Libertarian party candidate Gary Johnson should be included in the presidential debates.

But the senator did say that the 15% support threshold needed by presidential candidates to qualify for the official debates was "probably too high."

"It should be lower than that," Sanders said.

Sanders, however, brushed off polls that showed many of former millennial Sanders supporters backing either Johnson or Green Party candidate Jill Stein.

The Independent senator acknowledged that one of the two major-party candidates would almost certainly become president, and of the two, Clinton's positions on issues like climate change and college affordability were far closer to his own stances than those of Donald Trump.

"Either Hillary Clinton or Donald Trump is going to become president of the United States. And there is no question in my mind that Hillary Clinton is far, far, far and away the superior candidate," Sanders said.