Portsmouth, New Hampshire (CNN) Sen. Bernie Sanders of Vermont is the only Democratic presidential candidate who has been forthcoming about the costs and ramifications of "Medicare for All," Joe Biden told reporters Friday.

The comments by the former vice president, after a stop for ice cream while campaigning in New Hampshire, were an implicit shot at Sen. Kamala Harris of California and other 2020 rivals, and the most direct Biden has been in his criticism of their support for Medicare for All.

"Bernie's been very honest about it. He said you're going to have to raise taxes on the middle class. He said it's going to end all private insurance. I mean, he's been straightforward about it. And he's making his case," Biden said.

He was asked if other Democrats are doing so, as well.

"Well, so far, not. So far, not. They may," Biden said.

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