WATCH: Sanders says Manchin must specify spending objections

Sen. Bernie Sanders, a key supporter of Joe Biden’s $3.5 trillion reconciliation spending plan strongly criticized Sen. Joe Manchin after the West Virginia Democrat said he does not want to see the United States become “an entitlement society.”

Watch Sanders’ remarks in the player above.

“I am not exactly sure what he means by that,” Sanders said. “Does that mean that we end the $300 direct payments for working class parents, which have cut childhood poverty in this country as a result of the American Rescue Plan, in half?” Sanders asked rhetorically.

“Does Sen. Manchin not believe what the scientists are telling us, that we face an existential threat regarding climate change,” Sanders asked. “And that it is absolutely imperative that we move boldly to cut carbon emissions?”

Sens. Joe Manchin, D-W.Va., and Sen. Kyrsten Sinema, D-Ariz., want curb the bill’s cost and have been their party’s highest-profile holdouts. Manchin has insisted on holding the package to $1.5 trillion and has said he wants to means test some programs. Democratic leaders will need every vote in the 50-50 Senate and all but three in the House for victory.

In virtual meetings Monday and Tuesday with small groups of House Democrats, Biden said he reluctantly expected the legislation’s final version to weigh in between $1.9 trillion and $2.3 trillion, a Democrat familiar with the sessions said Tuesday.

WATCH: Manchin urges Senate leaders to ‘engage’ on debt

He told them he didn’t think he could do better than that, the person said, reflecting demands from some of the party’s more conservative lawmakers.

As Democrats make painful decisions about scaling down the measure, they are battling over whether to finance as many initiatives as possible but for less than 10 years, or to pick out top priorities and fund them robustly.

Big proposed increases in housing may be cut. Expensive proposed Medicare dental benefits might have to be scaled back. And a proposed extension of a more generous children’s tax credit might be temporary, effectively daring a future Congress to refuse to extend them.

That Medicare expansion, which also includes new coverage for hearing and vision, is competing for money against other proposals to expand Medicaid coverage and to extend bigger tax credits for people buying health insurance under President Barack Obama’s health care law.