Sen. Bernie Sanders Bernie SandersThe Hill's Campaign Report: Trump faces backlash after not committing to peaceful transition of power Bernie Sanders: 'This is an election between Donald Trump and democracy' The Hill's 12:30 Report: Trump stokes fears over November election outcome MORE (I-Vt.) responded on Tuesday to 2020 presidential rival Joe Biden Joe BidenPelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Hillicon Valley: Subpoenas for Facebook, Google and Twitter on the cards | Wray rebuffs mail-in voting conspiracies | Reps. raise mass surveillance concerns Fox News poll: Biden ahead of Trump in Nevada, Pennsylvania and Ohio MORE's criticism of his health care proposal, calling the former vice president "wrong."

In an interview with The Washington Post, Sanders called Biden's critique of his "Medicare for All" plan "absurd." He also knocked Biden's proposed plan.

“Times change, and we have got to go further,” Sanders said.

ADVERTISEMENT

“Of course he’s wrong,” he added of Biden's proposal, and said he would like to continue to debate the former vice president on the matter.

Biden on Monday unveiled a health care plan that would not lead to a Medicare for All system but would allow the purchase of a public health insurance option like Medicare.

“I understand the appeal of Medicare for All, but folks supporting it should be clear that it means getting rid of ObamaCare, and I’m not for that,” Biden said in a video on the plan. “I know how hard it is to get that passed. I watched it. Starting over makes no sense to me at all.”

Sanders, for whom Medicare for All has been a signature issue, also tweeted Monday criticizing Biden's proposal.

"At the end of the day, you’ve either got to be on the side of the people or the side of the health insurance companies," he wrote. "I know which side I’m on."

Biden and Sanders are both running for the 2020 Democratic presidential nomination. Biden has consistently been the front-runner in polling, while Sanders, who was once solidly in second place, has slipped in recent weeks.