The House late Thursday passed President Trump's proposal to rescind $15 billion in previously appropriated funding by the government that was never spent.

Lawmakers approved the bill in a narrow 210-206 vote, which was close because 17 Republicans voted against it.

The vote is meant to put conservatives at ease about the huge two-year spending deal lawmakers reached this year, which will increase spending by about $300 billion over that period of time. But the vote almost didn't happen.

The House Rules Committee added a revised package to its Wednesday schedule only a day after the White House sent the latest version to Capitol Hill. That amended bill was delivered after months of negotiations, and after Trump begrudgingly signed a $1.3 trillion omnibus spending deal in March.

President Trump and the White House worked closely with House Majority Leader Kevin McCarthy, R-Calif., on the package, entitled the Spending Cuts to Expired and Unnecessary Programs Act.

"As members, we are charged with being good stewards of taxpayer money. That is a responsibility we all have. It shouldn’t be a partisan exercise. And historically, it hasn’t been," McCarthy said on the House floor Thursday. "President Trump’s spending cut request is a straightforward and smart way to trim a bloated federal budget."

Conservatives were quick to line up behind the package, which they say is a step toward reining in government spending. Others say it will hurt good faith negotiations moving forward as government spending is set to expire at the end of September.

Democrats argued the package would hurt efforts to fund children's health insurance, even though the bill only cuts unspent money. About half of the unspent money cut would come from the Children's Health Insurance Program, or CHIP, and about $4.3 billion would come from the Department of Energy.

“After exploding the deficit with a GOP tax scam for the wealthy and well-connected, Republicans have the gall to invoke 'fiscal responsibility' in demanding a new rescissions package that attacks funding reserved for children’s health initiatives," said House Minority Leader Nancy Pelosi, D-Calif., in a statement after the White House released its proposal.

"Republicans are hypocritically insisting on clawing back every loose penny in our accounts for children’s health while giving away hundreds of billions of dollars in tax breaks for big corporations and the wealthiest," she added.

Republicans dispute the Democratic line about the CHIP program, and point to the 10-year reauthorization bill they passed as part of the January government funding deal to re-open the government.

"Republicans have made sure CHIP isn’t going anywhere. We have removed any uncertainty about the stability of funding for that program," McCarthy said. "The funds we are rescinding tonight were appropriated long ago and will not be used for their intended purpose now."

The bill will now move over to the Senate. Majority Leader Mitch McConnell, R-Ky., says he is open to considering the bill, but there are no guarantees it will get through the upper chamber.