WASHINGTON, Dec 13 (Reuters) - Democratic Senator Joe Manchin was noncommittal on Monday after discussions with President Joe Biden about a key $1.75 trillion social spending bill, but said "anything is possible" when asked if the bill could pass before Christmas. Manchin, a moderate who has stood as a stumbling block to some major Biden initiatives, told reporters "the conversations are positive" about the bill, which is a key part of the White House agenda. The pair spoke on Monday as Biden attempted to ease passage of the "Build Back Better" bill, which aims to bolster the social safety net and fight climate change. Months of disagreement among Democrats have held up the social spending legislation, leading the chair of Congress" large progressive Democratic caucus to voice exasperation on Monday at what she said were deliberate misrepresentations of the bill. U.S. Representative Pramila Jayapal criticized an analysis of the bill released on Friday by the nonpartisan Congressional Budget Office at the request of Senate Republicans, which found that the bill would add $3 trillion to the federal budget deficit over the next decade if all its programs ran that long. That conflicted with an earlier CBO analysis, based on provisions in the bill that would phase out some programs, that it would increase the deficit by $367 billion. Democrats argue that all of that would be offset by increased tax revenue. "We made tough choices to only fund certain programs for fewer years (because the) top line number had to come down," Jayapal wrote in a series of tweets. "It is completely illogical to impute a score on a non-existent bill & shows GOP is just trying to kill it," she said, referring to Republicans. The bill has already been scaled back in scope from $3.5 trillion. Top Senate Democrat Charles Schumer has said he hopes to pass the bill by Christmas. Jayapal agreed to corral most of the 95-member Congressional Progressive Caucus into voting for Biden"s major infrastructure bill in November on Democratic leadership"s promise that Build Back Better would pass. Progressive Democrats are decrying the lack of movement on the bill"s passage. "Forcing millions to start paying student loans again and cutting off the Child Tax Credit at the start of an election year is not a winning strategy," Representative Cori Bush, a first-term progressive Democrat, said on Twitter. Meanwhile, Democrats continued trying to resolve differences within the party on several components of Build Back Better. Democratic Senator Catherine Cortez Masto succeeded in having a provision removed from the bill that would have set a new federal tax on certain nicotine products mainly used in vaping. Cortez Masto, who is up for re-election next year in the swing state of Nevada, objected to the tax, which she said would violate Biden"s pledge to not raise taxes on anyone with an annual income below $400,000.