Sen. Joe ManchinJoseph (Joe) ManchinPavlich: The claim Trump let the mentally ill get guns is a lie Toomey to introduce bill broadening background checks for firearms Scott Walker backs West Virginia attorney general in GOP Senate primary MORE (D-W.Va.) suggested Sunday that Democrats would consider raising the debt limit with only 51 votes in the Senate. 

Democrats tried to pass a $1.1 trillion increase in the debt limit Saturday, but they failed to achieve the 60 votes needed to overcome a Republican filibuster.

On "Fox News Sunday," host Chris Wallace asked Manchin to explain Sen. Dick DurbinRichard (Dick) Joseph DurbinAmerica’s waning commitment to the promise of the First Amendment Senate rejects Trump immigration plan What to watch for in the Senate immigration votes MORE's (D-Ill.) comment that Democrats have "several somethings" they can use as a back-up plan to raise the debt ceiling and avoid default. 

"I would assume that they might be referring to the so-called 'nuclear option,'" Manchin said. "If you have to use that basically to keep this country from falling into default—do we go to 51 votes on the Senate side to prevent that from happening?" 

But Manchin said he hopes Democrats aren't forced to make that decision.

"I don't think we need to go that direction whatsoever, and I think we can come to an agreement," Manchin said.

The Democratic senator is part of a bipartisan group working with Sen. Susan CollinsSusan Margaret CollinsOvernight Tech: Judge blocks AT&T request for DOJ communications | Facebook VP apologizes for tweets about Mueller probe | Tech wants Treasury to fight EU tax proposal Overnight Regulation: Trump to take steps to ban bump stocks | Trump eases rules on insurance sold outside of ObamaCare | FCC to officially rescind net neutrality Thursday | Obama EPA chief: Reg rollback won't stand FCC to officially rescind net neutrality rules on Thursday MORE (R-Maine) on a bill that would raise the debt ceiling through January, reopen the government and delay the medical device tax (a provision of Obamacare) for two years. 

But that effort now appears dead, and the focus has shifted to negotiations between Senate Majority Leader Harry ReidHarry Mason ReidWATCH: There is no Trump-Russia collusion and the media should stop pushing this The demise of debate in Congress ‘North by Northwest,’ the Carter Page remake MORE (D-Nev.) and Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellLawmakers feel pressure on guns Bipartisan group of House lawmakers urge action on Export-Import Bank nominees Curbelo Dem rival lashes out over immigration failure MORE (R-Ky.).

The federal government will exhaust its borrowing authority and begin defaulting on its debt as soon as Thursday, according to the Treasury Department.