The House on Thursday ignored President Obama's veto threat and voted overwhelmingly in favor of a bill that would impose stringent background checks on all refugees from Syria, which could make it much harder for refugees to gain admittance into the United States.

The bill passed with such significant Democratic support that it calls into question whether President Obama's threatened veto of the bill can be sustained in the House. Democrats voted for the legislation even after a private briefing Thursday morning by White House Chief of Staff Denis McDonough and Homeland Security Secretary Jeh Johnson, which failed to convince Democrats to change their decision to support the legislation.

To get around Obama's veto, the House would need a two-thirds majority, and supporters reached that threshold on Thursday. The bill passed 289-137.

If it came down to a veto override and all members voted, 290 would be needed to override Obama's veto, and the House missed that number by one vote Thursday. Forty-seven Democrats voted for the bill along with almost every Republican, though it's possible Democrats might vote differently if it ever came down to overriding Obama's veto.

House Republicans noted that two Republicans missed today's vote, and would have voted for the bill, giving supporters 291. But even if true, Democratic leaders would only have to peel off a few Democratic votes to prevent an override.

Under the legislation, no Syrian or Iraqi refugee would be admitted into the United States until the nation's top federal law enforcement officials certify that they do not pose a safety or terrorism threat. Obama administration officials, including FBI Director James Comey, have told Congress they cannot fully investigate the backgrounds of refugees from war-torn Syria, so the bill would effectively block their entry.

Republicans described the bill as an attempt to create an extra layer of certainty when accepting immigrants from Syria, a needed steps after it became clear that one of the Paris attackers entered France as a refugee.

"This is an unprecedented vetting process to ensure dangerous people do not slip through the cracks," House Appropriations Committee Chairman Hal Rogers, R-Ky., said during floor debate.

The legislation now heads to the Senate, where the chamber rules will likely make consideration impossible until after the Senate returns from a week-long Thanksgiving recess. But Senate Minority Leader Harry Reid, D-Nev., has already indicated that Democrats would work to prevent the bill from moving ahead.

Speaker Paul Ryan, R-Wis. said he has discussed the legislation with Senate Majority Leader Mitch McConnell, R-Ky. who, like Ryan, has called for a pause in the Syrian resettlement program.

"He is very familiar with what we are doing," Ryan said.

On Wednesday, White House officials said the current vetting program for refugees is already thorough, and said the House legislation would "only to create significant delays and obstacles in the fulfillment of a vital program that satisfies both humanitarian and national security objectives." For those reasons, the White House said Obama would veto the bill.

Congressional Democrats countered the GOP plan with their own measures, including one sponsored by Reps. Bennie Thompson, D-Miss., and Zoe Lofgren, D-Calif., that would strengthen the vetting process for all refugees. It would require Homeland Security to verify the identity and records of all refugee applicants by several federal agencies.

Thompson called his bill a "pro-security, pro-compassion" measure that would keep the refugee program operating. But it failed to win passage on the House floor Thursday.

In the Senate, Dianne Feinstein, D-Calif., and Jeff Flake, R-Ariz., have sponsored legislation that would block Europeans from entering the United States without a travel visa if they have been in Syria during previous five years.

Democrats are also pushing legislation that would prevent anyone on the terrorist watch list from purchasing a gun.

Ryan said Thursday that a special House task force created in the wake of the Paris attacks would examine all the proposals, including those put forward by Democrats.

"This is the beginning of the process not the end of the process," Ryan said.