President Biden sat down with Sen. Joe Manchin (D-W.Va.) on Monday to discuss the administration's proposed $4 trillion spending package, which the moderate-minded lawmaker has floated busting up.

Manchin said Biden didn't take a position on if the proposal should be passed as one piece as opposed to two or more as some Democrats are pushing for, but indicated the issue came up as part of their sit-down at the White House.

"We talked about basically, are we going to do one, or do two or do three, things of that sort. Making sure we look at things that need to be done in traditional and human infrastructure, things of that sort," the senator told reporters at the Capitol after the meeting.

But asked if Biden expressed a preference on passing his plan as one bill or breaking it up, Manchin replied, "Not really."

"He just wants to get things accomplished. Gang I'm telling you, in his heart of hearts, he's all about let's be fair and move this country forward," he added.

Manchin is key to getting Biden's proposal, which is a combined $2.3 trillion infrastructure and jobs plan and a $1.8 trillion plan for families, passed through Congress.

Democrats expect they are likely to pass most, if not all, of the plan through reconciliation, a budget process that allows them to avoid the 60-vote filibuster.

That makes Manchin's support essential in the evenly divided 50-50 Senate. He already helped sink Neera Tanden's nomination to head the Office of Management and Budget, held Democrats' $1.9 trillion coronavirus bill in limbo for hours and has repeatedly and strongly come out against eliminating the legislative filibuster despite growing support within his party for such a step.

And there are already tension points on the spending plan.

Biden has pitched increasing the corporate tax rate to 28 percent to help cover the cost of his $4 trillion proposal. Manchin, however, has warned that he thinks that is too high but that he would support a 25 percent tax rate for corporations.

Manchin, speaking to reporters on Monday, said he and the president got into discussions about how to pay for the bill but, asked specifically about the corporate tax rate, he said they didn't get into details.

"He understands and he's up on everything, trust me, he knows what's going on. He's well versed in what's going on, and he understands," Manchin said.

Pressed on the size of the package, Manchin added that Biden didn't put out a "drop dead figure" but wanted to "make sure we meet that need" for Americans.

"I think in good faith we start working and finding out through a process where it goes into the committee, comes to the floor with amendments and what we end up with," he said.

The meeting with Manchin is one of several that Biden is having with lawmakers this week. He'll meet with the top four congressional leaders on Wednesday and a group of GOP senators on Thursday about infrastructure.

Sen. Shelley Moore Capito (R-W.Va.) led a group of Republicans in drafting a $568 billion infrastructure framework last month, though Senate Minority Leader Mitch McConnell (R-Ky.) has floated that Republicans could go up to $800 billion.

That still leaves Republicans and Biden far apart on both the spending levels and how to pay for it.

Manchin has floated breaking up Biden's package and focusing first on "core" infrastructure such as roads, bridges, rail and broadband that could get enough votes to defeat a filibuster.

"What we think the greatest need we have now, that can be done in a bipartisan way, is conventional infrastructure whether it's the water, sewer, roads, bridges, internet — things that we know need to be repaired, be fixed," he said at a press conference late last month. 

"Why don't you take the greatest need that we have and do it on something that we all agree on?" Manchin added.

He said during a West Virginia radio interview late last month that he thought $2.3 trillion as one package is too large. 

"In one chunk? Absolutely," Manchin said. "I think we should look at what we call conventional infrastructure."