Senate Majority Leader Chuck Schumer vowed Monday that the Senate will vote on President Joe Biden’s cornerstone social spending agenda “very early” in the new year, countering Sen. Joe Manchin who announced Sunday he would vote ‘no,’ all but dooming the bill as currently written.

In a biting letter to colleagues, Schumer writes that Manchin’s opposition will not “deter” Democrats from “continuing to find a path forward.”

After outlining the plight of Americans struggling to pay for prescription medicine and food for their families, Schumer wrote that the Senate will consider Build Back Better on the floor in the new year, and will continue voting on revised versions until an outcome is achieved.

In a thinly-veiled jab at the West Virginia Democrat, Schumer wrote that the Senate would take repeated votes “so that every Member of this body has the opportunity to make their position known on the Senate floor, not just on television.”

Manchin announced during an appearance on “Fox News Sunday” that he would vote against the Biden’s Build Back Better package after months of tense negotiations with the president and on Capitol Hill, citing concerns about inflation and the overall cost of the package.

“I’ve always said if I can’t go home and explain it to the people of West Virginia, I can’t vote for it. I cannot vote to continue with this piece of legislation. I just can’t. I’ve tried everything humanly possible. I can’t get there,” Manchin said Sunday.

Schumer’s move to force votes on the Senate floor would dare Manchin, and the other moderate Democratic holdout, Sen. Kyrsten Sinema of Arizona, to take a public vote against the package on which Biden has staked much of his domestic agenda.

In his first comments since triggering a harsh response from the Biden White House, Manchin told the West Virginia radio program “Talkline” Monday, “Basically, they retaliated. I figured they would come back strong” and said he was fine with a Senate floor vote.

“I’m not blaming anybody. I knew where they were, and I knew what they could and could not do,” Manchin said. “They just never realized it because they figured, ‘Surely to God, we can move one person. Surely we can badger it and beat one person up. Surely we get enough protesters to make that person uncomfortable enough they’ll just say, Okay, I’ll vote for anything just quit.’ But guess what? I’m from West Virginia. I’m not from where they’re from, and they can just beat the living crap out of people and think they’ll be submissive. Period.”

Negotiations over the $1.75 trillion package, which includes funding for in-home care, universal pre-K, an extension of the just-expired Child Tax Credit and Medicare expansion have gone on for months. All 50 Senate Democrats must vote together to advance the social spending package, and Manchin’s intransigence has proven to be a potentially insurmountable obstacle.

A blistering statement by White House press secretary Jen Psaki Sunday showed the administration’s frustration with Manchin. Psaki argued the senator’s bombshell announcement Sunday is “at odds” with what he indicated in private negotiations with Biden just last week — confirming the White House was caught off guard by Manchin’s news, and strongly criticizing the senator for the “sudden and inexplicable reversal of his position.”

“On Tuesday of this week, Senator Manchin came to the White House and submitted—to the President, in person, directly—a written outline for a Build Back Better bill that was the same size and scope as the President’s framework, and covered many of the same priorities,” Psaki said Sunday. “If his comments on FOX and written statement indicate an end to that effort, they represent a sudden and inexplicable reversal in his position, and a breach of his commitments to the President and the Senator’s colleagues in the House and Senate.”

Psaki took a less combative tone on Monday.

“I will say that from the president’s viewpoint, and I saw him this morning, he’s worked with Senator Manchin over the course of decades. They share fundamental values, they’re longtime friends. That has not changed.” she said. “And what’s most on the president’s mind is the risk of inaction. And if we do not act to get this legislation done, and the components in it, not only will costs and prices go up for the American people, but also we will see a trajectory and economic growth that is not where we want it to be.”

With Psaki calling Manchin and Biden “longtime friends,” ABC News Chief White House Correspondent Cecilia Vega asked Psaki point-blank: “Does the President feel betrayed by his friend?”

“I think our statement yesterday made pretty clear what we feel what was the factual depiction of events that happened. But again, the president sees Senator Manchin as somebody who is a longtime friend, somebody who has worked well together on and our objective and our focus now is moving forward,” Psaki replied.

ABC News Congressional Correspondent Rachel Scott reported Manchin and Biden spoke Sunday night, according to two sources familiar with the call who said the conversation was constructive and did end with some type of consensus that “talks” would continue in the new year but it’s unclear what the path forward looks like. The White House and Manchin’s office declined to comment.

Schumer’s effort to ratchet up pressure on the West Virginia moderate won’t end with Build Back Better. In his letter on Monday, Schumer said the Senate will also consider voting rights, and take challenging votes on whether to modify the Senate’s filibuster rule.

Under current Senate rules, 60 votes are needed to end a filibuster and proceed to debate on legislation. Senate Republicans have withheld votes and tabled multiple efforts to pass voting reform this session, leaving many Democrats advocating for a revision of the Senate rules.

But Manchin and Sinema have said for months they’re committed to upholding the rules requiring 60 vote to move forward on legislation. Sinema reaffirmed her commitment to blocking a reform of the Senate rules in a statement last week.

Still, Schumer said Monday he’ll force on-the-record votes on it.

“The American people also decry this deadlock. I believe our constituents deserve to know which Senators choose to hide behind ill-conceived and abused rules and which Senators prefer to restore Senate floor procedures to better align with the Founders’ intentions,” Schumer wrote. “Therefore, as with the BBB, Members will be given the chance to debate on the Senate floor and cast a vote so that their choice on this matter is clear and available for everyone to see.”

The Senate departed Washington on Friday for the remainder of the year. Schumer’s comments Monday spell a contentious return for Democrats in 2022.

Minority Leader Mitch McConnell weighed in on Manchin’s opposition to Biden’s Build Back Better Agenda in a Fox News Radio interview with Guy Benson Monday afternoon.

He said he was “shocked by the vitriol” with which the White House responded to Manchin’s remarks Sunday.

“It seemed to me that they were calling Senator Manchin a liar. I think that was not smart,” McConnell said. “This is a 50-50 Senate. It’s going to be 50-50 for another year. Believe me, that’s not the way I would have handled a disappointing vote like this.”

McConnell said he’s argued “for quite some time” that Manchin should join the GOP conference.

“I don’t know if Joe will ever become a Republican but I can tell you this for sure: the moderates are gone,” McConnell said. “It’s a completely uncomfortable fit for Joe. But that’s a decision ultimately he has to make we certainly welcome him to join us if he were so inclined.”

ABC News’ Trish Turner, Molly Nagle and Libby Cathey contributed to this report.