"I think Ocasio-Cortez is a brilliant, bright woman, but she won a primary," he said.
Ocasio-Cortez, for her part, has hit at Biden's centrist stances, warning he will depress turnout in a general election against President Trump.
"I think that he's not a pragmatic choice," the rising Democratic star said last month. "If you pick the perfect candidate like Joe Biden to win that guy in the diner, the cost will make you lose because you will depress turnout as well."
“And that’s exactly what happened to 2016. We picked the logically fitting candidate, but that candidate did not inspire the turnout that we needed," she said.