Democratic presidential candidate Bernie Sanders said he wished Hillary Clinton had picked Mass. Sen. Elizabeth Warren as her running mate over Virginia Sen. Tim Kaine.

"Would I have preferred to see someone like Elizabeth Warren selected by Secretary Clinton? Yes, I would have," Sanders told moderator Chuck Todd during an interview on NBC's "Meet the Press" Sunday.

The Vermont senator said Kaine has views that are "more conservative" than his, which he has described as democratic socialist.

Warren, who was elected in 2012, has made a name for herself as a progressive focused on reining in big banks and Wall Street, areas Sanders focused on during his campaign.

But Sanders' campaign manager Jeff Weaver diverged a bit from his boss's assessment of Kaine.

"If people wanted a sort of more overtly progressive candidate — I certainly appreciate that," Weaver told MSNBC "AM Joy" host Joy Reid on Sunday. "I live in Virginia. I voted for Tim Kaine in the past. He's my senator. You know, his politics seem to be animated a little bit by his Catholic faith, and I sort of appreciate that. And hopefully, as he finds his way as the vice president, he'll be more animated by that part of his experience."

Sanders endorsed Clinton last month but has yet to drop out of the race for the nomination despite not having the number of delegates and superdelegates necessary to secure a win.

Sanders admitted "there are a lot of reasons why one loses," but he did not blame the Democratic National Committee, even after emails leaked by WikiLeaks on Friday indicate the party was more supportive of Clinton's campaign than his.

He said no one has personally apologized to him in the wake of the scandal.